




SUMMARY TECHNICAL REPORT 
OF THE 

NATIONAL DEFENSE RESEARCH COMMITTEE 




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classification of any material. 



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SUMMARY TECHNICAL REPORT OE DIVISION 8, NDRC 


VOLUME 1 


THE PREPARATION 
AND TESTING OF EXPLOSIVES 


OFFICE OF SCIENTIFIC RESEARCH AND DEVELOPMENT 
VANNEVAR BUSH, DIRECTOR 

NATIONAL DEFENSE RESEARCH COMMITTEE 
JAMES B. CONANT, CHAIRMAN 

DIVISION 8 

RALPH A. CONNOR, CHIEF 




WASHINGTON, D.C., 1946 


NATIONAL DEFENSE KESEAliCH COMMITTEE 


James B. Coiiant, Chairman 
Bicliard C. Tolinaii, Vice Chairman 
Roger x\dams Army Representative' 

Frank B. Jewett Navy Representative^ 

Karl T. Compton Commissioner of Patents^ 

Irvin SteMTirt, Executive Secretary 


^Army representatives in order of service: 


Maj. Gen. G. V. Strong 
Maj. Gen. R. C. Moore 
Maj. Gen. C. C. Williams 
Brig. Gen. W. A. Wood, Jr. 

Col. E. 


Col. L. A. Denson 
Col. P. R. Fayinonville 
Brig. Gen. E. A. Regnier 
Col. M. ]M. Irvine 
A. Routheau 


^Navy representatives in order of service: 

Rear Adm. H. G. Bowen Rear Adm. J. A. Purer 

Capt. Lybrand P. Smith Rear Adm. A. H. Van Keurne 

Commodore H. A. Schade 
^Commissioners of Patents in order of service: 

Conway P. Coe Casper W. Ooms 


NOTES ON THE ORGANIZATION OF NDRC 


The duties of the National Defense Research Committee were 
(1) to recommend to the Director of OSRD suitable projects 
and research programs on the instrumentalities of warfare, 
together with contract facilities for carrying out these projects 
and programs, and (2) to administer the technical and scien- 
tific work of the contracts. More specifically, NDRC func- 
tioned by initiating research projects on requests from the 
Army or the Navy, or on requests from an allied government 
transmitted through the Liaison Office of OSRD, or on its 
own considered initiative as a result of the experience of its 
members. Proposals prepared by the Division, Panel, or 
Committee for research contracts for performance of the 
work involved in such projects were first reviewed by NDRC, 
and if approved, recommended to the Director of OSRD. 
Upon approval of a proposal by the Director, a contract per- 
mitting maximum flexibility of scientific effort was arranged. 
The business aspects of the contract, including such matters 
as materials, clearances, vouchers, patents, priorities, legal 
matters, and administration of patent matters were handled 
by the Executive Secretary of OSRD. 

Originally NDRC administered its work through five di- 
visions, each headed by* one of^^ie NDRC members. These 
were : * j 

Division A — Armor and Ordnance 
Division B — Bombs, Fuels, Gases, & Chemical Problems 
Division C — Communication and Transportation 
Division D — Detection, Controls, and Instruments 
Division E — Patents and Inventions 


In a reorganization in the fall of 1942, twenty-three ad- 
ministrative divisions, panels, or committees were created, 
each with a chief selected on the basis of his outstanding work 
in the particular field. The NDRC members then became a 
reviewing and advisory group to the Director of OSRD. Tlie 
final organization was as follows: 

Division 1 — Ballistic Research 

Division 2 — Effects of Impact and Explosion 

Division 3 — Rocket Ordnance 

Division 4 — Ordnance Accessories 

Division 5 — New Missiles 

Division G — Sub-Surface Warfare 

Division 7 — Fire Control 

Division 8 — Explosives 

Division 9 — Chemistry 

Division 10 — Absorbents and Aerosols 

Division 11 — Chemical Engineering 

Division 12 — Transportation 

Division 13 — Electrical Communication 

Division 14 — Radar 

Division 15 — Radio Coordination i 
Division 16 — Optics and Camouflage 
Division 17 — Physics 
Division 18 — War Metallurgy 
Division 19 — Miscellaneous 
Applied Mathematics Panel 
Applied Psychology Panel 
Committee on Propagation 

Tropical Deterioration Administrative Committee 


Library of Congress 



201 5 460881 


NDRC FOREWORD 


A S EVENTS of the years preceding 1940 revealed more 
- and more clearly the seriousness of the world 
situation, many scientists in this country came to 
realize the need of organizing scientific research for 
service in a national emergency. Itecommendations 
which they made to the White House were given care- 
ful and sympathetic attention, and as a result the 
National Defense Research Committee [NDRC] was 
formed by Executive Order of the Rresident in the 
summer of 1940. The members of NDRC, appointed 
by the President, were instructed to supplement the 
work of the Army and the Navy in the development 
of the instrumentalities of war. A year later, upon the 
establishment of the Office of Scientific Research and 
Development [OSRD], NDRC became one of its units. 

The Summary Technical Report of NDRC is a 
conscientious effort on the part of NDRC to summar- 
ize and evaluate its work and to present it in a useful 
and permanent form. It comprises some seventy vol- 
umes broken into groups corresponding to the NDRC 
Divisions, Panels, and Committees. 

The Summary Technical Report of each Division, 
Panel, or Committee is an integral survey of the work 
of that group. The first volume of each group’s report 
contains a summary of the report, stating the problems 
presented and the philosophy of attacking them, and 
summarizing the residts of the research, development, 
and training activities undertaken. Some volumes may 
be ‘^state of the art” treatises covering subjects fo 
which various research groups have contributed in- 
formation. Others may contain descriptions of devices 
developed in the laboratories. A master index of all 
these divisional, panel, and committee reports which 
together constitute the Summary Technical Report 
of NDRC is contained in a separate volume, which 
also includes the index of a microfilm record of per- 
tinent technical laboratory reports and reference 
material. 

Some of the NDRC-sponsored researches which had 
been declassified by the end of 1945 were of sufficient 
popular interest that it was found desirable to report 
them in the form of monographs, such as the series 
on radar by Division 14 and the monograph on sam- 
pling inspection by the Applied Mathematics Panel. 
Since the material treated in them is not duplicated 
in the Summary Technical Report of NDRC, the 


monographs are an important part of the story of 
these aspects of NDRC research. 

In contrast to the information on radar, which is 
of widespread interest and much of which is released 
to the public, the research on subsurface warfare is 
largely classified and is of general interest to a more 
restricted group. As a consequence, the report of 
Division 6 is found almost entirely in its Summary 
Technical Report, which runs to over twenty volumes. 
The extent of the work of a division cannot therefore 
be judged solely by the number of volumes devoted 
to it in the Summary Technical Report of NDRC : 
account must be taken of the monographs and avail- 
able reports published elsewhere. 

In most of the projects undertaken by NDRC it 
was necessary to begin with a program of fundamental 
research in order to understand the problems to be 
solved. To Division 8 came many requests for funda- 
mental research in problems concerning high explo- 
sives and propellants. The information obtained from 
these studies was useful in designing many new weap- 
ons and developing several new manufacturing proc- 
esses, including an improved process for RDX and 
the development of molded composite rocket propel- 
lants and albanite, a propellant which eliminates 
flash from Navy guns. The fundamental information 
obtained from these studies, which has also been ap- 
plied to programs outside NDRC efforts, will be of 
lasting usefulness and is perhaps the Division’s great- 
est achievement. 

To carry out the work, the Division, together with 
its contractors, employed the services of a group of 
highly skilled scientists, under the leadership of first 
C. 1>. Ivistiakowsky and later Ralph A. Connor. This 
Summmary Technical Report, prepared under the 
direction of the Division Chief and authorized by 
him for publication, is a record of the Division’s 
accomplishments and a tribute to the scientific integ- 
rity of the men who loyally served in it. They deserve 
the grateful appreciation ^g>f the Nation. 

Vannevar Bush, Director 
Office of Scientific Research and Development 

J. B. CoNANT, Chairman 
National Defense Research Committee 


V 






FORE\^ORD 


T he summary of the work carried out by Division 
8 of the Xational Defense Research Committee 
[XDRC] — The Division of Explosives — is intended 
to give the reader an understanding of the scope of 
the Division’s activities and to present briefly the 
results. Therefore, only limited experimental data are 
included : it is expected that those who wish more than 
a superficial knowledge of a particular field will refer 
to the original reports which are cited as references 
in the body of the summary. The work of Division 8 
has been closely related to the work of Divisions *2 and 
3 and it may be helpful to describe here the distribu- 
tion of activities. 

It was originally intended that Division 8 should 
include in its program the effects of explosives in 
liquid and gaseous media, while Division 2 should 
explore the effects in solids and in semi-solids, su(?li 
as soils. AVhile this assignment of responsibilities did 
guide the planning of programs it was not logical to 
follow it exactly; thus Division 8 undertook research 
on fragmentation, cavity charges, and certain phases 
of the work on air blast. In June 1944, the program on 
underwater explosives and explosions and the Division 
8 work on air blast was transferred to Division 2 ; the 
summaiy* report of Division 2 will therefore be of 
interest to those interested in high explosives since it 
c-ontains both Division 2 and Division 8 information 
on air blast, underwater explosions, and terminal 
ballistics. 

In the XDRC program on roc-kets. Division 3 car- 
ried out the design of rocket weapons and most of the 
work on conventional processes for solvent-extruded 
and dry-extruded double-base powders. This work is 
described in the summary report of Division 3. Divi- 
sion 8 carried out the research on new rocket powders, 
on new processes for conventional powders, and on 
stability determination and anahJical methods for 
all propellants. 

Division 8 did not attempt to set up and carry out 
a comprehensive program covering the entire field of 
explosives. The initial program was almost entirely 
of a fundamental and long-range character, with 
emphasis on synthetic research with some fundamental 
theoretical and experimental work on high explosives. 
As the fundamental research began to produce re- 
sults, the high explosives program changed to the 
development of proc-esses and the major emphasis in 
high explosives was directed toward the physical 
chemistry of explosives and, later, toward the applica- 


tion of this knowledge to the evaluation of weapons 
and the development of new weapons. The summarv 
of the work on high explosives will therefore contain 
information on the following broad subjects : synthetic 
work, the development and application of methods for 
the evaluation and c-omparison of explosives and loaded 
munitions, the development of explosive compositions 
and devices, studies of the effects of explosions, and 
studies of the processes of detonation and its initiation. 

After the program on high explosives was under 
way, Division 8 began its program on rocket propel- 
lants and, still later, on gun propellants. The summary 
of the work on propellants will therefore deal with 
the following: theory' of the burning of propellants, 
molded c-omposite propellant for rockets and jet pro- 
pulsion units, solvent-extruded composite propellants 
for rockets, cast propellants for jet propulsion devic-es, 
gun propellants, and methods for the analysis and 
testing of propellants. 

The last general field to be studied by Division 8 
conc-erned trac-ers and igniters; the major objective 
was improved stability. Later, the development of a 
dim igniter was undertaken. 

The evolution of the Division 8 program was the 
result of problems which originated within the Serv- 
ices or which were suggested by the Division and then 
sponsored by the Services. Those programs which re- 
sultetl in practical developments were the result of 
g(Kxl cooperation, and it is a pleasure to express the 
Division’s appreciation to those within the Bureau 
of Ordnance, Army Air Forces, and Ordnanc*e De- 
partment who c-ontributed to this work. 

This summarv’ has been constructed from a larsre 
number of reports on individual problems and has 
been written by persons having first-hand familiarity 
with the projects about which they have written. Manv 
of these authors have delayed their return to their 
permanent positions or have contributed their free 
time to the preparation of their summaries. Acknowl- 
edgment is made here to these persons as a group; 
they are named individually at the beginning of each 
section of the summary. The value of the summary 
is due directly to their cooperation in preparing this 
material and to the efforts of Dr. A. H. Blatt who 
planned the summary, guided the preparation of the 
various sections, and edited the final draft for submis- 
sion to the Summary Reports Group. 

Ralph A. Coxxor 
Chief, Division 8 




CONTENTS 


CHAPTER PAGE 

Introduction 1 

1 Preparation of High Explosives 3 

2 The Properties of High Explosives 34 

3 Applications of High Explosives 50 

4 Experimental Studies of Explosive Phenomena .... 65 

5 The Theory of the Detonation Process 83 

6 Propellants 89 

7 Tracers and Igniters 151 

Glossary 153 

Bibliography 155 

OSRD Appointees 174 

Contract Numbers 175 

Service Projects Numbers 178 

Index 


181 




INTRODUCTION 


T his section of the Summary Technical Report 
will attempt to summarize the specific adoptions 
and developments of Division 8 which will be of gen- 
eral interest. It should be emphasized, however, that 
the greatest contributions of the Division will probably 
not be enumerated in listing the specific accomplish- 
ments. In practically every problem that was presented 
it was necessary to carry out fundamental research 
in order to understand the problems to be solved. The 
fundamental information so obtained and the advice 
of the Division 8 personnel experienced in these fields 
has been felt in the design of many weapons and in 
the developments of many programs which cannot be 
attributed directly to NDRC. This fundamental in- 
formation will be of lasting usefulness and perhaps 
represents the greatest achievement of Division 8. 

A new and improved process for the manufacture of 
RDX was developed by the Division and was utilized 
for the production of about 360 tons of RDX per day. 
In addition to developing the process, additional prob- 
lems were solved, including the incorporation of RDX 
with TXT in the preparation of Composition P>, a 
process for the recovery of waste acid from the mother 
liquor, and the development of a substitute for bees- 
wax in order that Composition A might be available 
on the scale necessary. This also led to an extensive 
research program on Torpex, and ultimately methods 
were developed for desensitizing this material and for 
the prevention of gassing during the storage of Tor- 
pex loaded munitions. 

A iirocess was developed for the preparation of tlie 
intermediates for Haleite, and improvements were 
made in the nitration process. A plant to produce this 
explosive and its intermediates, based upon this work, 
was beginning production when the war ended. Stabil- 
ity studies were an important part of both the pro- 
pellants and high explosives programs, and the results 
obtained in such investigations were directly respon- 
sible for changes in the 5" A A shell which decreased 
the probability of explosion when these shells were 
held in hot guns, for a change in the refining pro- 
cedure of PETX, for the improved stability of alumi- 


nized explosives, including Torpex which was men- 
tioned above, and for the adoption of a binder for 
tracer compositions which was used in production and 
gave improved stability to tracer ammunition. 

Molded composite rocket propellants were developed 
and were ultimately made in diameters up to 12 inches. 
Grains having a diameter of 8V2 inches were success- 
fully used for launching the JB-2 weapon, and a plant 
to manufacture these charges was about 00 per cent 
completed when the war ended. 

In order to eliminate flash from Navy guns a new 
propellant, Albanite, was developed, adopted by the 
Navy, and plans to produce this material were being 
made when the war ended. This propellant required 
the use of an explosive material, DINA, which had not 
l)een prepared prior to the war, and a process for 
manufacturing this was develo])ed by Division 8. 

One of the solvent extruded composite propellants 
developed by Division 8 was produced for use in the 
bazooka for the elimination of particle blast. It was 
known as BBP (Blastless bazooka powder). 

Among the incompleted projects of the Division which 
may ultimately result in important weapons, the follow- 
ing subjects of investigation may be mentioned : 

1. Shaped Charge Bombs 

2. Antisubmarine Shaped Charge Bombs 

3. The Shaped C'harge Follow-Through Rocket 

4. Shaped (diarge Warheads for Naval Torpedoes 

b. Antisubmarine Shaped (3iarge Follow-Through 

Bombs 

6. Liquid Explosives 

7. RDX Gun Powders 

8. Powder and Head for the Super Bazooka 

9. Powder for the Super 4.5" Rocket 

10. Improved Plastic Explosives 

11. A process for the Preparation of Picric Acid 
from Benzene in One Step 

12. The Explosive and Liner for a Spherical Gre- 
nade (BEANO) 

The detailed descriptions of these and other projects 
are to be found in the seven chapters of the Summary 
d'echnical Report which follow. 


1 




Chapter 1 


PREPARATION OF HIGH EXPLOSIVES 


A s PART of its work on liigli explosives, Division 8 
■ of the National Defense Research Committee 
[NDRC] undertook to prepare a number of candidate 
materials in sufficient quantity to permit an evalua- 
tion of their explosive properties. Some of the candi- 
date explosives were chosen because they had been 
suggested in the open or classified literature; others 
were chosen because they, or the intermediates lead- 
ing to them, had become available as a result of de- 
velopments in the organic chemical industry in the 
past twenty-five years. This program naturally re- 
sulted in the preparation of a large number and 
variety of compounds. 

For those candidate explosives whose properties 
merited the effort, attempts were made to develop 
commercially applicable methods of synthesis. When 
these attempts were successful and the explosive 
seemed likely of adoption, the syntheses were put 
through the pilot plant stage. When a development 
reached this point it was usually desirable to make a 
rather detailed study of the mechanism of the reac- 
tions involved in order to determine what by-products 
were formed. In addition studies of the preparation 
and properties of analogs of the successful candidate 
explosive were called for. The most important devel- 
opments were the combination process for preparing 
liDX, tlie synthesis of Haleite, the synthesis of 
DINA, and the oxynitration of benzene to yield picric 
acid. These and the less spectacular results of the 
program are described in Sections through 1.9 
below. 

The work described in the last paragraph dealt 
with pure compounds. Much additional work was de- 
voted to explosive mixtures, for World War II saw 
the utilization in quantity of plastic explosives, of 
explosive compositions in which a powerful but sensi- 
tive explosive like EDX is desensitized by admixture 
with wax and/or a less sensitive explosive like TNT, 
and of aluminized compositions. Work with these 
three groups of explosives is detailed in Sections 1.10 
through 1.12. 

“This section is based on a summary prepared by Marvin 
Carmack. 


11 THE PREPARATION OF RDX BY 
THE DIRECT NITROLYSIS OF HEXAMINE 

One of the first exjfiosives problems investigated by 
the NDRC was the preparation of RDX. Studies of 
the direct nitrolysis of hexamine were begun in the 
latter part of 1910. Somewhat later most of the effort 
was diverted to the alternative procedure, known now 
as the combination process. Work on the direct ni- 
trolysis is summarized in the present section, and 
the development of the combination process and a 
comparison of the two processes are treated in Section 
1.2 below. 

In January 1941 a report*^ summarizing the work 
of the NDRC investigators carried the conclusion 
that there was then sufficient information available 
to permit the commercial production of RDX, but 
that much additional work was necessary in order to 
bring the cost of the material down to a reasonable 
figure.^ 

In the report just mentioned the most detailed 
NDRC information came from the investigators work- 
ing at the Pennsylvania State College. This group 
studied both batch and continuous nitrolysis of 
hexamine. The most favorable results in batch runs 
were obtained with a ratio of 10 parts of nitric acid of 
at least 92% concentration to one part of hexamine, 
the reaction being carried out during 25 minutes at 
25 to 30 C ; the yield was 65 to 70%. The presence 
of sulfuric acid was found to be deleterious, and the 
addition of any of a number of salts either had no 
effect or decreased the yields of cyclonite. 

For the continuous preparation of cyclonite by 
nitrolysis a small glass unit was developed. This unit 
had an output of 2.5 kg oD cyclonite per day. The 
proportions of niateifials ,a|nd yields were essentially 
the same in the batch and the continuous processes, 
the chief difference in the methods being the manner 
of mixing the hexamine and nitric acid. The reaction 

^ This report contains not only the results of the NDRC in- 
vestigations but also data from Picatinny Arsenal, the Her- 
cules Powder Co., E. I. du Pont de Nemours and Co., and 
from the Canadian investigators working on Project CE-12 
at the University of Toronto. 


3 



4 


PREPARATION OF HIGH EXPLOSIVES 


c]iaml)er consisted ol‘ a glass tube 1() iiini in dianiettn’ 
into wliicli the strong nitric acid at between — 10 and 
— 5 C could be led and mixed with solid hexaniine in- 
troduced by means of a mechanically operated alu- 
minum screAV device. Dissipation of the heat of reac- 
tion was the most difficult problem of the continuous 
process. 

The final report of the rennsylvania State College 
group gave detailed information on the development 
of a continuous process for the nitrolysis of hexaniine." 

The results were liased partly upon batch runs un- 
der varied conditions, and partly upon results ol)- 
tained in three different models of apparatus for 
continuous nitrolysis. 

In liatch runs the best yield was obtained by the 
addition of 10 g of hexaniine to 100 parts of 99% 
nitric acid (N’^O^-free) at temperatures not exceed- 
ing 0 C during a period of 80 minutes. After the reac- 
tion mixture had stood for an additional 45 minutes, 
it was drowned in 500 ml of water and furnished a 
90% yield of cyclonite. When the nitrolysis was car- 
ried out at 8 to 10 C during one hour, with an addi- 
tional one-hour holding period, a yield of 84.8% was 
obtained. 

The cyclonite obtained liy drowning the reaction 
mixture in water and filtering was finely divided and 
contained impurities which made it difficult to dry 
the product comjiletely. Moreover, the filtrates obtained 
were unstable and liable to undergo spontaneous fume- 
off. Purification of the product hy recrystallization 
from 70% nitric acid, or acetone, or 1-nitropropane 
was recommended. 

A much more satisfactory method for the isolation 
of the cyclonite involved the initiation of a controlled 
fume-off to destroy formaldehyde and other by-prod- 
ucts by oxidation to carbon dioxide with the formation 
of recoverable nitrogen oxides. The fume-off could be 
induced by pouring the reaction mixture, after a suit- 
able period of holding to complete the nitrolysis, into 
sufficient hot water at 85 to 90 C to result in a final 
nitric acid strength not exceeding 70%. As soon as 
the vigorous and exothermic fume-off was proceeding 
smoothly with the evolution of quantities of nitrogen 
tetroxide, the temperature could be reduced to 75 C 
until the reaction was complete. Nitrogen oxides were 
collected in a cold trap. The acid remaining in the 
fume-off vessel consisted of 30 to 50% nitric acid with 
a layer of solid crystalline cyclonite. x\.fter the oxida- 
tive destruction of the by-products, the cyclonite was 
easily recovered in a state of high purity (mp 204 C) 
by filtering and washing. The product was nicely crys- 


talline and easily dried, in contrast to material isolated 
by drowning. The fiime-olf method involved very little 
loss of cyclonite unless the nitric acid strength at'ter 
dilution exceeded 70% concentration, above which 
some decomposition of the cyclonite occurred. The 
solid product isolated following fume-olf contained 
only about 0.08% of occluded acidity, which could 
be decreased by prolonged boiling in water or by re- 
crystallization from an organic solvent. 

The simplest apparatus for continuous nitrolysis 
of hexaniine consisted of a spherical glass reactor of 
100-ml volume designed to operate at a reaction vol- 
ume of 50 ml. It was provided with four openings in 
the top: an inlet for 98% white nitric acid from a 
precooling unit, a thermometer, an air-driven stirrer, 
and a mechanically driven aluminum screw feed for 
the introduction of powdered hexaniine. A hfth open- 
ing in the bottom of the reactor was sealed to an in- 
verted U tube which served to regulate the reaction 
volume and to peiinit the continuous withdrawal of 
reaction mixture into a holding vessel. The whole unit 
was immersed in a cooling bath. In a typical run, 98%; 
white nitric acid and hexaniine were introduced in the 
weight ratio of 14.2 to 1. During a run of 3% hours, 
a total Aveight of 1,360 g (79.7%) of cyclonite Avas 
produced from 1,080 g of hexaniine. The temperature 
Avas held betAATen — 3 and 5 C during the nitrolysis. 

The second apparatus for continuous nitrolysis Avas 
constructed from a block of aluminum into Avhich a 
hole 2 in. in diameter had been drilled to serve as a 
reaction chamber. The reaction chamber AA'as provided 
Avith stirrer, thermometer, an aluminum screAV feed 
deAice for the introduction of hexaniine, and entrance 
and exit openings for nitric acid and reaction mixture, 
respectively. The aluminum block Avas cooled during 
the reaction by circulating a stream of dry air, chilled 
to loAv tempei’ature by liquid air, through the jacket 
surrounding the reactor. The nitric acid Avas precooled 
to betAA^een — 10 and 0 C by jiassage through a coil 
chilled Avith cold air. In one run of three hours’ dura- 
tion, a total Aveight of 2,100 g of funied-olf cyclonite 
Avas prepared from 1,850 g of hexaniine (72% yield). 
During the run the reaction temperature Avas main- 
tained betAveen — 5 and 0 C; the mixture A\'as held for 
fifteen minutes to complete the nitrolysis before the 
fume-olf Avas initiated. Quantitative data on the cool- 
ing requirements A^^ere included in the report. 

The third and largest continuous reactor consisted 
of a cylindrical, flat-bottonied aluminum pot reactor 
Avith a volume of three quarts, designed to operate 
Avith a reaction volume of one quart. It Avas provided 


PREPARATION OF RDX BY DIRECT NITROLYSIS OF HEXAMINE 


5 


willi a siiiipk* si*[)arat()rv fiiniu'l lor Iho iiitrodiiotioii 
of strong nitric acid, a funnel for the introductioji of 
})o\vdercd licxainine, an air-driven stirrer, an oveiilow 
side-tube for removal of reaction mixture, and a coil 
of dt) ft of O/^o-in. 01) aluminum tubing for cooling 
the reaction mixture. iVntane at a temperature be- 
tween — 80 and — 60 0 was piinii)ed through the 
coil at such a rate that the reaction temperature was 
held at approximately 0 C. Detailed data on the cooling 
re(piirements Avere recorded to aid in the design of 
reaction units of plant scale. In a typical run at 0 C 
using an acid hexamine ratio of 16.4 by weight, a 
yield of 65.5^ of dry, fumed-olf cyclonite was iso- 
lated. The rate of })roduction of cyclonite was of the 
order of o pounds ])er hour. 

It was estimated that a oO-gallon Pfaudler unit 
should he able to produce at least 555 pounds of cy- 
clonite per hour. 

^ ^ ^ Tinportant Variables in the Direct 
Nitrolysis Process 

XiTHic A(ui) Stuenutii and Ratio of 
XiTKic Acid to Hexamine 

When a fixed weight ratio of 10 parts of nitric acid 
to one part of hexamine Avas used in a series of batch 
nitrolyses at 0 C, it Avas found that the yield of cyclo- 
nite Avas a nearly linear function of the strength of 
nitric acid betAveen 88 and 99^, the yields varying 
from about 5 to 90% in that range. All runs AA^ere 
made Avith an addition time of 30 minutes, folloAved 
by a holding time of 30 minutes. In another series of 
experiments the strength of nitric acid Avas held con- 
stant at 98%, and the Aveight ratio of nitric acid to 
hexamine Avas varied. Above the ratio of 11/1 the 
yields of cyclonite remained api)roximately constant, 
but beloAV that critical ratio yields fell off rapidly, 
reaching 64% at a ratio of 8 parts of 98% nitric acid 
to one ])art of liexamine. 

1 1 EACTIOX TeMPEHATUK E 

The yields Avere essentially constant at various tein- 
[)ei’atures up to about 5 C. Al)ove 5 C the yields be- 
came progressively loAver as the tem])erature increased ; 
at 52 C only 53% of cyclonite Avas olfiained Avith 10 
parts of 98% nitric acid to one part of hexamine. 
It AA'as recommended that the temperature of nitroly- 
sis he maintained betAveen 0 C and 5 (/ not only to 
obtain the maximum yield of cyclonite, hut also for 
maximum safety of operation. On the other hand it 


Avas i)oiided out tbat at a tenii)eratiire of 8 lo 10 (■ tbe 
yield is only sligbtly loAver tban 0 to 5 (/ so that tbe 
economy elfected by reduced infrigeration require- 
ments at tbe bigber tem})eratures inigbt outAveigh the 
slight loss in yield. 

The heat of the nitrolysis reaction Avas found to 
be of the order of 500 calories per gram of hexamine. 
The removal of the heat of reaction and the prevention 
of local overheating AAdiere particles of solid hexamine 
come into contact Avith fresh nitric acid AA'ere found to 
be the most difficult factors to control in the nitroly- 
sis reaction, ])articularly in the continuous reactors. 
The time of addition of hexamine in batch runs or the 
rate of feed of reactants in the continuous reactors, 
as Avell as the degree of agitation, have an important 
bearing on the control of the reaction temperature. 

PuniTV OF THE XlTPlC AciD 

The ])resence of nitrogen tetroxide in the nitric 
acid is undesirable, since the oxide seems to make the 
reaction mixture unstable and liable to fume-off. The 
higher the percentage of nitrogen oxides, the loAver 
the temperature at AAdiich the fume-off is likely to 
occur. Another undesirable point suggested in connec- 
tion Avith the presence of nitrogen tetroxide is that it 
probably results in the formation of traces of trinitro- 
sotrimethylenetriamine ; this material loAvers the sta- 
bility of the cyclonite. Xitric acid containing no more 
than 0.15% of nitrogen tetroxide apparently gave sat- 
isfaetory results. 

In an effort to find possible catalytic effects, a num- 
ber of substances, mostly inorganic salts, AA^ere added 
to the nitrolysis mixture in a series of runs; in gen- 
eral tbe yields of cyclonite AA^ere either unaffected or 
Avere loAvered. Xo desirable effects aaxu’c observed Avith 
any of the added substances studied. 

Time of Addition of Hexamine 

It Avas suggested that this variable is related to the 
influence of temperature, since the decreases in yield 
i-esulting from too rapid addition of hexamine to the 
nitric acid are probably due to local overbeating. Tbe 
proper rate of addition aa411 tberefore he that AAdiich 
does m)t exceed the cajiacity of the apparatus to re- 
move the heat of nitrolysis. The same statement ap- 
])lies to the rate of feed of the reactants in the contin- 
uous reactors. 

Effect of Sthuhng 

Vigorous stirring of the hexamine Avith the nitric 
acid is desirable to promote rapid solution of the solid 


[ro\ MDKXddAtft 


6 


PREPARATION OF HIGH EXPLOSIVES 


in the liquid and to avoid uni'avorahle loc'al tempera- 
ture and concentration ell'ccts. 

Effect of Holding Time defoee ^\'oI^K-UF of 

XlTKOLYSIS MiXTUEE 

The reaction of hexamine was at lirst considered 
to be complete as soon as the hexamine had dissolved, 
hut later investigations showed that holding the reac- 
tion mixture for an additional 15 to 20 minutes re- 
sulted in a gain of 5 to 10^ in the yield of cyclonitc. 
A holding period was made a part of the standard 
procedure. 

Effe(’ts of Vaeious Methods of Isolating 
Gyclonite 

The controlled fuine-olf of the diluted reaction mix- 
ture was found to give a granular product of satis- 
factory purity and excellent crystalline properties. If 
the strength of nitric acid during the funie-olf does 
not exceed 70 % by Aveight, there is very little loss of 
cyclonite by decomposition. The procedure involving 
the droAvning of the reaction mixture in cold Avater 
had the disadvantages that the solid cyclonite con- 
tained impurities AA'hich made it difficult to dry and 
handle, AA’hile the filtrates Avere unstable and tended 
spontaneously to undergo fume-off. 

At about the time that the final report discussed 
in the preceding pages appeared, reports reached this 
country from England describing the continuous ni- 
trolysis process developed there. The British process, 
knoAvn noAV as the WooBvich process, Avas in pilot 
plant operation, plans for acid recovery Avere AA^ell 
under Avay, and designs for a plant to produce (iO tons 
of EDX per AA'eek AA'ere in preparation. In vieAV of this 
situation, and because of the promising results being 
obtained in the study of the synthesis of KDX using 
acetic anhydride (see Section 1.2), AA^ork on the ni- 
trolysis of hexamine by XDRC investigators AA'as 
suspended. 

^luch later, in April 1944, interest in the nitrolysis 
of hexamine Avas revived. As a preliminary to the set- 
ting uj) of a research program on this subject, a de- 
tailed revieAv of the literature on the direct iiiU-olysis 
])rocess Avas prepared.^ 

The changing military situation, hoAv^ever, and the 
need for the available investigators to Avork on another 
problem led in late dune 1944 to the postponement 
of the experimental program, and in the fall of 1944 
the decision Avas made not to undertake experimental 
AA'ork on the nitrolysis of hexamine. 


12 THE COMBINATION PROCESS FOR THE 
PREPARATION OF RDX(B)« 

Within a. short time after research on 1U)X had 
been started, NDRC Avas advised that CVinadian in- 
vestigators had obtained a 40^^ yield of BDX by the 
interaction of approximately equivalent amounts of 
formaldehyde, ammonium nitrate, and acetic anhy- 
dride. The process may be represented ideally as 
folloAvs : 

SIICTIO + 3NI1,N03 + G(Cll3C0)20-^ 

NNO., 

/ \' 

CUj OH2 

I I +ricii3€0ji 

O3NN NNO3 

\ / 

CHj 

This method avoids the destruction of formaldehyde 
and the enormous recovery of nitric acid characteristic 
of the nitrolysis reaction, but requires the use and 
recovery of a large amount of acetic anhydride. 

At this time the United States had a large capacity 
for acetic anhydride, and the Avaste of formaldehyde 
and recovery of nitric acid in the direct nitrolysis of 
hexamine Avere considered more serious than the high 
consumption of acetic anhydride in the Canadian 
process. Consequently a study of the neAv Canadian 
method Avas begun. This Avas done first at the Univer- 
sity of Michigan and later more extensiA’ely at Cornell 
University. The original Canadian method consisted 
of mixing all the reagents cold and Avarniing until a 
vigorous reaction set in. It Avas shoAvn very early at 
MichigaiP that better yields AA'ere obtained by adding 
portioiiAvise to a flask an intimate mixture of am- 
monium nitrate and paraformaldehyde, and a slight 
excess of acetic anhydride containing a trace of nitric 
acid. The reaction mixture is maintained at 75 C and 
stirred vigorously during the process. After the addi- 
tion is completed the mixture is heated for a short 
period, diluted Avith AVTirm Avater, chilled and the pre- 
cipitated 1U)X removed by filtration. 

At Cornell University^’® the Canadian process Avas 
subjected to a more thorough study, during AAdiich it 
Avas concluded that the best results Avere obtained by 
adding one mole of paraformaldehyde to a mixture of 
1.25 moles of ammonium nitrate and 2.5 moles of 
acetic anhydride. After isolation in the usual Avay, 
the BDX Avas recrystallized from 55 % nitric acid. 

®This section is based on summaries prepared by S. R. Aspin- 
all and Ralph Connor. 


COMBINATION PROCESS FOR PREPARATION OF RDX(B) 


7 


StTulios were made of the optimum ratio of ingredi- 
ents, the o])timum temperature of reaetion, the rela- 
tive merits of different forms of formahleliyde, and 
the etfeet of free nitric acid and buffers. These studies, 
as well as a search for catalysts, failed to produce any 
sigiiiticant improvement in the standard procedure, 
outlined above, which yielded about 55% of the theo- 
retical amount of 1\DX calculated from formaldehyde. 
This i)rocess was used for a short time for full-scale 
manufacture in Canada, but active investigations of 
this method by XDRC ceased about December 1941 
because of the promise of another process — the com- 
bination process which is described below. 

As has been pointed out, the direct nitrolysis, ideal- 
ly represented by reaction (1), 

(CTU),X, + 411X03-^ 

XXO., 

/ 

CH, CH^ 

I “ I +3HCH0 + XH,X03 (1) 

0.,XX XXO 2 

\ / 

Cl I, 

must be carried out with a large excess of nitric acid 
which results in the destruction of one-half of the 
formaldehyde introduced, and requires that an enor- 
mous nitric acid recovery system be made an integral 
])art of the explosives plant. On the other hand the 
Canadian process, ideally represented by reaction (2) 

dllClIO + :3XII,X()3 + b(Cn 3 C 0 ) 30 -^ 

XXO, 

/ \ 

CH, ('ll, 

I I + ia(’ir3t'02it (3) 

O3NN XNO, 

\ / 

CITj, 

requires a large amount of acetic anhydride, half of 
which is consumed because formaldehyde and am- 
monia (as ammonium nitrate) are introduced into 
the reaction rather than hexamine (the dehydrated 
equivalent of formaldehyde and ammonia). 

Since the two by-products of the nitrolysis reaction 
(1) are raw materials for the Canadian reaction (2), 
it is apparent that, if the nitrolysis reaction would 
occur under conditions favorable for the Canadian 
reaction, it would be possible to eliminate the disad- 
vantages of both. By simple addition of reactions 
(1) and (2) one obtains reaction (3) : 


(CH2)6N4 + 4HNO3 + 2NH4NO3 + 6(Cri3C0)20-^ 
XXO, 

/ \' 

CH, CI 4 

I I +13('H3C03lI (3) 

O3NN NNOj 

\ / 

CH, 

Tn this reaction one makes use of the formaldehyde 
and ammonium nitrate formed in the nitrolysis and 
obtains two moles of EDX from each mole of hexa- 
mine and each 6 moles of acetic anhydride; further- 
more, there is no nitric acid to be recovered. By the 
spring of 1941 this reaction, known as the combina- 
tion process, had been run successfully at the Univer- 
sity of Michigan, and by late 1941 it had shown such 
promise that all XDKC work on EDX after that time 
was directed toward its development. A great many 
modiffcations of the basic reaction were investigated 
at Michigan,^’^ Cornell,^’® and Pennsylvania State 
College,® but the following may be considered typical. 

Ammonium nitrate and acetic anhydride Averc 
placed in a flask and, while the mixture Avas stirred 
at 75 C, the folloAving three liquids AA^ere introduced 
concurrently and proportionately : acetic anhydride, 
concentrated nitric acid, and a solution of hexamine 
in glacial acetic acid. The final mixture Avas held for 
a short time at 75 C, diluted Avith Avater to 30% acetic 
acid, and simmered to hydrolyze unstable reaction by- 
products, AAiiich arc a mixture of Aarious nitrated and 
acetylated derivatives of hexamine fragments. After 
simmering, the slurry is cooled and the precipitated 
EDX removed by filtration. The yield is 78% of the 
theoretical amount (2 moles) of EDX melting at 
199 C. By dissolving the ammonium nitrate in the 
nitric acid, the process is made to consist of feeding 
three liquids (ammonium nitrate dissolved in nitric 
acid, hexamine dissoh^ed in acetic acid, and acetic 
anhydride) into the reaction flask. This in effect put 
the reaction on a continuous basis and later a reactor 
Avas designed Avhich Avas more suitable for continuous 
operations. This reactor consisted of a U-shaped tube 
Avith an arm connecting the upper ends of the U. 
During operation, the U tube is filled Avith reaction 
mixture Avhich is circulated rapidly by a pump (pro- 
peller), and the three liquids are fed into one arm 
of the tube at the same rate that the reaction mixture 
overflows from the other. The effluent reaction mixture 
is held until a suitable volume has accumulated ; it is 
then diluted, simmered, cooled, and the crude EDX 
removed by filtration. 


8 


PREPARATION OF HIGH EXPLOSIVES 


'J’lie crude prodiud from the comhiiiatioii process 
contains traces of acetic acid even after thorough 
washing, so it is desirable to recrystallize the product 
to reduce the acidity essentially to zero. A much more 
important reason for recrystallization is connected 
with the nature of the explosive product itself. All 
material produced by the combination process (as 
well as the Canadian process) consists of a mixture 
of RDX and HMX, the latter being present in 
amounts varying from 3 to 8% of the total when the 
process is carried out under optimum conditions. This 
mixture of EDX and HMX is hereafter designated 
as EDX(B). HMX is cyclotetramethylenetetranitra- 
niine (the eight-memhered ring analog of RDX) and 
may arise from the eight-memhered ring present in 
hexamine. 

HMX is equivalent to EDX in power and is supe- 
rior to RDX in chemical stability. HMX exists in 
four polymorphic modifications, the stable one 
{/ 3 ) of which shows about the same sensitivity to im- 
pact as RDX ; however, the unstable polymorphic 
modifications of HMX are very sensitive, especially 
in certain crystal modifications.^^’^^ Therefore, al- 
though the presence of HMX in the product from the 
combination reaction is not deleterious per se, it is 
essential for safety in manufacture and handling that 
the HMX be present only as the /^-polymorph. The 
best method of insuring the exclusion of the unstable 
sensitive polymorphs is to recrystallize the product 
under equilibrium conditions. This can be done from 
any one of a great many solvents provided precipita- 
tion is done sloAvly and with adequate agitation. A 
convenient and economical way of conducting the 
crystallization is to dissolve the crude RDX in hot 
acetone and then blown in steam until the acetone is 
completely removed, leaving a slurry of RDX in 
Avater. The aqueous acetone Avhich distils is suitable 
for immediate recovery; the acid-free mixture of 
RDX-/? HMX is removed by filtration. This mate- 
rial is the end product of the preparative procedure 
and is ready -for incorporation with other materials 
such as TNT, wax, or oil (Section 1.11). 


of the reaction Avas understood. This work Avas con- 
ducted by alloAving hexamine to react Avith each and 
all of the other ingredients of the combination proc- 
ess, in various ratios and under various conditions. 
By this means it is possible to prepare a large number 
of compounds, some of Avhich are actually formed as 
by-products in the combination process and some of 
Avdiich are neAxr isolated under conditions prevailing 
in the process. For example, by treating hexamine 
Avith acetyl nitrate (an equimolecular mixture of 
acetic anhydride and nitric acid AcgO + HNO 3 ^ 
AcONOg -|- AcOH) one obtains a series of four com- 
pounds Avhich represent different degrees of attack of 
the hexamine molecule by the reagent. If 1 mole of 
acetyl nitrate is used, the product is a derivative of an 
unl)roken hexamine molecule ; 2 moles of acetyl nitrate 
produce a cyclic pentamethylenetetramine derivative 
in AAdiich one carbon atom is lost l)ut the basic ring 
structure of hexamine is preserved; 3 moles of acetyl 
nitrate produce a derivative of linear pentamethyl- 
enetetramine in Avhich one carbon atom of the original 
hexamine is lost and the ring structure is destroyed; 
4 moles of acetyl nitrate produce a derivative of linear 
tetramethylenetriamine in AAdiich an additional car- 
bon atom and a nitrogen have been lost. 

The product from 1 mole of hexamine and 4 moles 
of acetyl nitrate, Avhich has the structure CHgCOg- 
CH2N(N02)CH2N(N02) CH2N(N02) CH2O2CCH3 
and is designated BSX, is apparently the end prod- 
uct of the interaction of the tAvo materials and actu- 
ally appears as a by-product of the combination re- 
action ; it is one of the unstable compounds hydro- 
lyzed in the simmering process. Although BSX is 
the only oife of the acetyl-nitro derivatives of the 
linear polymethyleneamines positively demonstrated 
to be present in crude RDX(B), it is quite likely that 
other related compounds are likewise present and are 
destroyed by simmering. By conducting the combina- 
tion process in the cold, BSX is the major product of 
the reaction.^ 

If the product obtained from hexamine and 2 
moles of acetyl nitrate, Avhich has the structui-e 


1.2.1 The Mechanism of the Reaction 

In connection Avith the development of the com- 
bination process an attempt Avas made to determine 
the exact chemical mechanism by Avhich RDX is 
formed. This study Avas undertaken primarily be- 
cause of the feeling that Avays to improve the yields 
beyond those Avhich were obtained by an empirical 
approach Avould be arrived at only if the true nature 


OgNN 


NNO 


2 




CH 


2 


COMBINATION PROCESS FOR PREPARATION OF RUX(B) 


9 


and is designated Dl’T, is isolated and then treated 
Avith 1 or 2 moles of acetyl nitrate, one obtains two 
eoni})onnds which are not the same as those obtained 
from hexaniiiie and 3 or 4 moles of acetyl nitrate 
respectively, indicating that DPT and the products 
from hexamine and 3 or 4 moles of acetyl nitrate have 
a common precursor other than hexamine. 

It has been mentioned that 41 MX is always pro- 
duced in amounts ranging from 2 to 8^ in the com- 
bination process. It is of interest that the process 
may be carried out so as to obtain good yields of a 
product consisting mainly of HMX** (contaminated by 
a little 1\DX). Since it is possible to destroy pref- 
erentially the I\1)X by an alkaline digestion, this con- 
stitutes an excellent synthesis of pure IIMX.^^ It is 
also possible to obtain IIMX by nitration of DPT 
although the evidence is clear that DPT is not an in- 
termediate in the formation of HMX from hexamine, 
acetic anhydride, nitric acid, and ammonium nitrate. 

In the course of these studies on the mechanism of 
the combination process an enormous amount of in- 
formation was collected on the fundamental chemistry 
of hexamine, but in spite of the large amount of data 
collected, and the thorough study of all of the prod- 
ucts which were obtained, the true nature of the re- 
action has not been discovered nor has it been pos- 
sible to improve the yields over those obtained by 
using methods developed empirically. 

2 Pilot Plant Development 

It has been indicated that by the summer of 1941 
work in the United States, Canada, and Great Britain 
showed there were three practical methods for the 
synthesis of RDX. The nitrolysis reaction was the 
first of these developed and was operated on a large 
scale in England and the United States in spite of 
the inherent disadvantages that one-half of the 
formaldehyde which is introduced is lost, and that 
large amounts of nitric acid must be handled and re- 
covered. The Canadian method does not require 
nitric acid ; and, at the time under consideration, the 
supply of acetic anhydride was not critical. The 
amount of acetic anhydride required in the Canadian 
process was such that the problem of handling liquids 
was less serious than in the nitrolysis process. Theo- 

‘^A 73% yield of pure HMX was obtained in one-step batch 
operation, and a 60% yield of pure HMX in continuous 
operation. Continuous operation was used for the preparation 
of some 25,000 pounds of HMX at the Holston Ordnance 
Works. The earlier alternative and much less satisfactory 
preparation of HMX from hexamine via DPT is described 
in reference 20. 


rctically it sliould l)e p()ssil)le by this reaction to con- 
vert all of the formaldehyde to II DX and in this 
way overcome the second disadvantage of the nitroly' 
sis reaction. Studies on a pilot plant scale, con- 
firmed in a production plant, showed, however, that 
this process was only slightly more economical of 
formaldehyde than the nitrolysis rtraction. Labora- 
tory work on the combination process indicated the 
possibility of obtaining 80^ of the theoretical 
amount (2 moles) of RDX as RDX(B), thereby pro- 
ducing over twice as much explosive per pound of 
formaldehyde as was produced by the other methods. 
Although the process involved the recovery of acetic 
acid, the amount involved was about 40^ of that 
necessary in the Canadian process, and, therefore, 
this method seemed the most promising of all from 
the standpoint of economy of formaldehyde and in 
economy of handling liquids for recovery. 

In view of the al)ove considerations and of the facts 
that the Canadian process was being studied on a pilot 
plant scale in Canada and that the nitrolysis process 
had been studied on a large scale in Britain, it was 
decided to conduct pilot plant studies of the combina- 
tion process. At the time this decision was made, 
laboratory experimentation had been centered largely 
upon the use of hexamine dinitrate as a starting ma- 
terial. The first RDX(B) pilot plant, built and op- 
erated by the Western Cartridge Company, was there- 
fore devoted to a batch process using hexamine 
diuitrate as a starting material. 

In December 1941, a study of the recovery of 
acetic acid from the nitration mother liquor was un- 
dertaken under a contract with the Tennessee East- 
man Corporation. At this time various considerations 
led to a decision to undertake a study of the prepara- 
tion of RDX(B) in a second pilot plant under con- 
tract with E. I. du Pont de Nemours and Company. 
By this time, it had been shown that hexamine was 
satisfactory starting material for the nitration, and 
the du Pont pilot plant studied a batch process based 
on the nitration of hexamine.^^ 

Due to delays encountered in starting operations 
of the du Pont pilot plant and to the urgency of 
having waste acid for recovery studies, a contract for 
the construction and operation of a third RDX(B) 
pilot plant was negotiated in January 1942 with the 
Tennessee Eastman Corporation. After preliminary 
experimentation, it was decided that this pilot plant 
would use hexamine as a starting material in a con- 
tinuous nitration. Since these pilot plants represented 
the only source of RDX in the U. S. at this time, and 




10 


PREPARATION OF HIGH EXPLOSIVES 


since Coin})ositioii 1> was clcsiml for experiinontal 
purposes, the Tennessee Eastman pilot plant carried 
out a pilot plant study of the preparation of Com- 
position B. The results of the Tennessee Eastman 
studies on acid recovery, RDX(B) preparation, and 
Composition B preparation are reported together.'^^ 

As a result of the pilot plant studies, it was decided 
that hexaniine dinitrate would not be used as a start- 
ing material. This was due primarily to the fact that 
hexaniine dinitrate is itself an explosive and its use 
represented an additional hazardous operation. Fur- 
thermore it is hygroscopic, and drying facilities 
would require additional construction and would be 
hazardous. The continuous nitration gave appreciably 
higher yields than the batch nitration, and the process 
adopted for production by the Army Ordnance De- 
partment was, therefore, the continuous process using 
hexaniine as a starting material. The Tennessee East- 
man Corporation pilot plant was transferred to the 
Ordnance Department in August 1942 for training 
personnel for the production plant. The Holston Ord- 
nance IVorks of the Tennessee Eastman Corporation 
was designed for the production of 170 tons per day 
of EDX(B) by the continuous process and was later 
expanded to produce somewhat more than double this 
quantity. 

1.2.3 Description of Continuous Process 
and Incorporation 

The process as developed in the XDBC-Tennessee 
Eastman pilot plant was as follows. Three solutions 
were introduced simultaneously and equivalently into 
the nitrator. These solutions consisted of (1) acetic 
anhydride, (2) hexaniine dissolved in acetic acid, and 
(3) ammonium nitrate in nitric acid. The nitrator 
used can be visualized in a simplified form as a long 
U tube with a tube near and connecting the upper 
ends of the U. Actually the U tulie was built in a 
horizontal position and the liquid contained in it was 
circulated very rapidly through the tube by means of 
a pump. RDX(B) was formed during the circula- 
tion and the resultant slurry overflowed into a hold- 
up tank. After a suitable quantity of the reaction 
mixture had been collected, it was diluted with water 
to aliout 35 to 40% acid and heated in a simmer 
tank at about 95 C for approximately IV 2 hours. 
The IiDX(B) was waslied and collected on a trolley 
filter and the wet BDX(B) dissolved in 85% ace- 
tone. The acetone was removed by distillation with 
steam, the slurry passed through a colloid mill, and 
the IiDX(B) collected on a trolley filter was then 


added to molten TNT, with or without wax, under 
water. The water was removed by decantation and 
the slurry heated in the incorporator until the re- 
maining water was completely vaporized. Drops of 
molten C^oniposition 13 Avere alloAved to fall on a con- 
tinuous stainless steel belt, giving pellets resembling 
chocolate buds in size and shape. 

Acid Recovery® 

The mother liquor obtained by the filtration of the 
diluted reaction mixture A\^as adjusted to pH 2.0 by 
the addition of alkali, in order to neutralize a small 
amount of excess nitric acid. Distillation in a primary 
still gave a nitrate-free distillate containing 30 to 
40% acetic acid and a residual sludge AA’hich Avas 
discarded. It AA'as considered that this residue from 
large-scale operations Avould be suitable for a fer- 
tilizer. The aqueous acetic acid distillate Avas con- 
verted to glacial acid by azeotropic distillation and 
converted to acetic anhydride by conventional indus- 
trial processes. 

Refining 

The various by-products AAdiich accompany RDX- 
(B) haA^e been described elseAAdiere. With the ex- 
ception of HMX, these by-products are decomposed 
during the simmer operation and no further refining 
is necessary to remove these impurities. Eefining does, 
hoAA’ever, giA’e additional assurance that BSX and re^ 
lated compounds are completely destroyed. Neither 
the simmer operation noi' acetone purification removes 
HMX, Avhich occurs in quantities of 3 to 8% in 
lU)X(B). It has been pointed out earlier that HMX 
in no Avay affects adversely the quality of the prod- 
uct as long as only the ^-polymorph is present. 
While the process can ])e operated so as to give the 
^-polymorph, acetone refining is an additional 
safeguard against the formation of sensitive HMX 
polymorphs. One of the important considerations in 
introducing acetone refining Avas the fact, AAdiich first 
became evident during pilot plant operations, that 
this presented a method for controlling the particle 
size of the product and, hence, the pourability of the 
Composition B derived from it. This step also de- 
creases the acidity of the product and greatly sim- 
plifies the production of acid-free material, since oc- 
cluded acetic acid is extremely difficult to remove 
from BDX(B) by Avater Avashing or boiling. It 
should, perhaps, be added that investigations by the 

®Some work had been done earlier at the University labo- 
ratories on the iiroblein of acid recovery. 24 


COMBINATION PROCESS FOR PREPARATION OF RDX(B) 


11 


Holston Ordnance Works, under the auspices of the 
Army Ordnance Department, have indicated that in 
some vavs cyclohexanone is superior to acetone as a 
solvent for refining. 

1.2.6 Analytical and Test Methods 

^lost of the control methods are described in the 
reports from the pilot plants. These methods are of 
too limited interest to justify complete discussion in 
this report. Other laboratories collaborated in a num- 
ber of problems concerned with control operations. 
An investigation was made of the melting points of 
samples of Rl)X(B) and a special apparatus for de- 
termining the melting point was designed.^® A meth- 
od was devised using a glass electrode for adjusting 
the pH of the aqueous acetic acid before primary 
distillation.^*’ A specific conductance measurement in 
a special cell was recommended for measuring the 
concentration of water in the solution of ammonium 
nitrate in nitric acid which is used in the nitration. 

A special apparatus was constructed which permitted 
the determination of water in RDX(B) and in Com- 
position B in quantities as low as 0.1^. This pro- 
cedure involved conductometric titration with acetic 
anhydride in acetic acid containing sulfuric acid.“^ 
Various methods were developed for the determina- 
tion of HMX in RDX(B).^® One of these methods, 
chromatography, requires detailed mention. 

A thorough study was made of the chromato- 
graphic behavior of BDX and nine related com- 
pounds.^®’^' The primary objective was to provide a 
method for the analysis of production lots of RDX 
and IiDX(B) in order to determine the significance 
of the melting points of the two products. It was 
shown that the product from the Holston Ordnance 
Works (combination process), although sometimes 
melting as low as 188 C, contained materials other 
than BDX and HMX to the extent of only a few 
thousandths of one per cent, whereas the material 
from the Wabash River Ordnance Works (nitrolysis 
process), although never melting below 200 C, con- 
tained several hundredths of one per cent of cyclonite 
oxide and HMX and extremely small traces of other 
unidentified compounds. These experiments confirmed 
the earlier belief that the lower melting point of the 
combination product was in no way a reflection of 
inferior quality. As a preparation for the chroma- 
tographic analysis of these plant samples, the chro- 
matographic behavior of the compounds related to 
RDX, which conceivably could be by-products of 
either process, were investigated. 


^ ^ ^ Special Problems 

A number of problems involved in the develop- 
ment operation were of sufficient urgency to justify 
the assignment of other groups to assist the pilot 
plant personnel. The problem of HMX polymorphism 
has been discussed elsewhere in this report. The heat 
of reaction in the formation of RDX(B) was deter- 
mined for both batch and continuous nitrations.’'*- 
In the early pilot plant operations, difficulty was en- 
countered in the formation of a scale on the walls of 
the nitrator.^^ This was shown to depend upon the 
heat transfer in the equipment, and it was found that 
the coating could ]:»e removed by heating the nitra- 
tion mixture to a slightly higher temperature or by 
adding a mixture of acetic acid and acetic anhydride. 
Proper construction of the nitrator eliminated this 
difficulty. Small-scale experiments were performed in 
order to determine the hazards which might result 
if feeds to the nitrator were accidentally stopped.®^ 
Medical studies on the health hazards involved in the 
process indicated that these were not greater than 
those encountered in the manufacture of other mili- 
tary explosives. RDX(B) taken internally is toxic 
and produces in animals convulsions which may be 
controlled by the administration of nembutal. Con- 
tact with fumes from the nitration mixture may pro- 
duce dermatitis, but no evidence was obtained of 
severe systemic toxicity from the manufacturing op- 
erations or from RDX(B) itself.^® The studies were 
useful in making recommendations regarding health 
precautions in the full-scale plant. 

1 2.8 Raw Materials Requirement 

On the basis of pilot plant studies running con- 
tinuously for twenty-eight days, the yield of RDX(B) 
per pound of hexamine was 2.622 lb. The production 
of one pound of RDX(B) required 0.39 lb of hex- 
amine, 0.77 lb of acetic acid, 0.66 lb of ammonium 
nitrate, 2.05 lb of acetic anhydride, and 0.79 lb of 
nitric acid. In acetone refining, 0.068 lb of acetone 
was lost per pound of RDX(B). In neutralizing the 
mother liquor, 0.44 lb of sodium hydroxide was re- 
quired per pound of RDX(B). Pilot plant studies 
of acid recovery indicated that 0.18 lb of acetic acid 
would be lost per pound of RDX(B) produced. In 
all, 148,727 lb of crude and 142,932 lb of refined 
Rl)X(B) were produced in the pilot plant. A total 
of 221,070 lb of Composition B was produced. It 
should be pointed out that, while this scale of opera- 
tions gave a reasonably clear picture of the process, 


E-QNFrnr*;NflST^ 


12 


PREPARATION OF HIGH EXPLOSIVES 


the continuous operation of the large-scale plant has 
resulted in some modification of the above figures. 

^ ^ ^ Comparison of Processes 

The batch process studied by the du Pont Com- 
pany gave a yield of 2.4 lb of EDX(B) per pound of 
hexamine. The raw material requirements differed 
very little from those of the continuous process, and 
it should be emphasized that it is perfectly feasible 
to prepare EDX(B) by hatch operations. Although 
the continuous process has some advantages, it is 
easy to visualize a situation in which availability of 
equipment might justifiably lead to a decision to use 
batch operations in preference to continuous. 

The comparison of 2.62 lb of EDX(B) per pound 
of hexamine by the continuous process with 1.17 lb 
of EDX by the conventional process probably appears 
more favorable than is actually warranted. In general, 
it seems probable that the combination process would 
be the preferred one. In time of war ammonia oxida- 
tion units and equipment for methanol and ammonia 
are likely to be in great demand. Since the combina- 
tion process requires much less nitric acid, less form- 
aldehyde, and less ammonia than the nitrolysis, it 
would he preferred unless acetic acid, acetic anhy- 
dride, and the equipment for manufacturing these 
were in critical condition. Since 98% nitric acid can 
be made and the oxide and dilute acid from the nitrol- 
ysis process can he recovered quite cheaply, a com- 
petitive demand for acetates might make the nitrol- 
ysis process the logical one for large-scale operations. 
The differences in cost of the product are probably 
less decisive than the availability of equipment and 
raw materials in determining the method to be used 
for the production of EDX. 


13 HALEITE^ 

The first investigation in this country of the prepa- 
ration and explosive properties of ethylenedinitra- 
mine, officially designated as Ilaleite by the Services,® 
was begun at the Eicatinny Arsenal about 1933. 
ffaleite was prepared from ethylenediamine by the 
following three-step process. 

^This section is based on a summary prepared by S. R. 
Aspinall. 

®The name Haleite was given to ethylenedinitramine by 
Ordnance Committee Item 40,757 of June 17, 1943. Prior to 
this action the substance was referred to as EDNA. 


CH2XH2 


CH2NH2 

Ethylenediamine 


(C2Hs)2C03 


CH^NH 
\ 
CO 


CH^NH 

Ethyleneurea 


CII2NII 


\ 

CO 


CH^XH 


HNO3 


CII2NNO2 

\ 

CO 

/ 

CH2NN02 

Dinitroethyleneurea 


C 


\ 

CO 




H2O 


CH,NHNO, 


CH2NHNO2 

Haleite 


This process suffers from two disadvantages : the over- 
all yield is only 42% of the theoretical amount; and 
the initial step, the reaction between ethylenediamine 
and ethyl carbonate, requires the use of high pressures 
and temperatures over an extended period of time. 
However, the explosive properties of Haleite were of 
sufficient interest to lead to the recommendation by 
the Eicatinny Arsenal that further work should be 
done on the preparation of the material, and it was 
indicated that Haleite would be of great military 
interest if it could be prepared for 50 cents or less 
per pound. 

With this background Division 8 began work in the 
fall of 1940 on the synthesis of Haleite. Since assur- 
ances had been received that ethylenediamine could 
be purchased in quantities as large as 40 tons per day 
at a cost of 25 cents per pound, the work was directed 
toward a synthesis of Haleite that would avoid the 
unsatisfactory step in the Eicatinny Arsenal process 
— the preparation of ethyleneurea from ethylenedia- 
mine and ethyl carbonate. Two approaches were in- 
vestigated: the first was a synthesis of Haleite that 
did not involve ethyleneurea as an intermediate; the 
second was an improved synthesis of ethyleneurea 
from ethylenediamine. 

Laboratory studies showed that ethylenediamine 
reacted smoothly with ethyl chloroformate at 80 C 
and at atmospheric pressure to form the dicarbethoxy 
derivative (I). Nitration of (I) and subsequent hy- 
drolysis of the nitration product furnished Haleite in 
an overall yield of 87% based on ethylenediamine 


fViXFi r!K\in\l 


HALEITE 


13 


CH 2 NII 2 


CILNHCO.CJi, 


CICO 2 C 2 H 5 


HNO. 




CH2XHCO2C2H5 

(I) 


CH^NtlNO^ 

H 2 O 

C1T2X(X02)C02C2TI5 ^ CII 2 XHXO 2 

All alternative procedure utilizing diacetylethylene- 
diamine (II) as an intermediate was also developed. 
This procedure gives a 76% yield of Haleite. 


CII^XH, 

I (CH3C0)20 

CH 2 XII 2 ^ 


CH2XHCOCH3 


HN03 

CH2XHC0Cn3 ^ 

( 11 ) 


CH2X(X02)C0CH3 CH 2 XHXO 2 


H20 

CH2X(X02)C0CH3 ^ CH 2 XHXO 2 


Xeither of these processes was put into pilot plant 
operation.^®'^’’ 

Two methods were developed for the conversion of 
ethylenediamine to ethyleneurea.®®'^^ 

1. Ethylenediamine and carbon dioxide heated at 
220 C and 820 atm for 30 minutes furnish ethyl- 
eneiirea ; 


(TT^Xn^ 

C02 


(iIIjNII 

\ 

CO 

/ 

CH^^iTH 


but this synthesis, like that from ethylenediamine 
and ethyl carbonate, requires high temperatures and 
pressures and does not give an outstandingly high 
yield. 

2. Ethylenediamine and urea heated in aqueous 
solution at atmospheric pressure furnish ethyleneiirea 
in quantitative yield. 

* 


CTT 3 XII 2 

+ XIT 2 COXH 2 

CH 2 XH 2 


> 


CIT^XTT 

\ 

CO + 2XH 

/ 

CII 2 XH 


3 


The ammonia evolved can be treated with carbon di- 
oxide and reconverted to urea. 

The procedures outlined above provided satisfactory 
syntheses of Haleite starting from ethylenediamine. 


However, at this stage in the work it was learned that 
the earlier assurances of an adequate supply of ethyl- 
enediamine at a price of 25 cents per pound were in 
error; and that ethylenediamine would be available 
only at a price of more than 50 cents per pound. This 
made it necessary to develop either a synthesis of 
ethyleneurea which did not involve ethylenediamine 
or a synthesis of ethylenediamine itself. 

A synthesis of ethyleneurea from ethylene glycol 
was first worked through.®®’'^^’^^ 


CH^OH 

+ XH 3 COXH 2 

CH^OH 


CH^-XH 

\ 

CO + 2 H 2 O 

/ 

CH 2 -XH 


In practice this reaction takes place in two steps. One 
mole of ethylene glycol is heated at atmospheric pres- 
sure for ten hours with five moles of urea. The prod- 
uct is an ethyleneurea polymer which, on heating with 
water, furnishes ethyleneurea. The four moles of ex- 
cess urea are hydrolyzed to ammonia and carbon diox- 
ide, but the ammonia can be reconverted to urea. Since 
at the time the process was under study there was 
ample unused urea capacity available, this was a seri- 
ous, but not a fatal, disadvantage. Consequently the 
process was put through pilot plant trials. From these 
trials it was estimated that a plant capable of pro- 
ducing 10 tons per day of ethyleneurea at a cost of 
45 cents per pound could be built for $1,000,000, and 
a plant capable of producing 60 tons per day at a 
cost of 40 cents per pound could be built for 
$4,000,000. 

Attention was next turned to the development of a 
synthesis of ethylenediamine. The successful synthesis 
consists of the following steps. 


CH 2 O +HCX — > HOCH^CX (98% yield) 


HOCH2CX + XH3 — ^ H2XCH2CX + H2O 

(82% yield) 

H2XCH3CX + 2H2 — H2XCH2CH2XH2 

(88% yield) 

The raw materials used in this process are cheap and 
available; the reactions proceed smoothly, rapidly, 
and in good yields ; only the third step, the hydrogena- 
tion, requires high pressures. Since the hydrogenation 
is a continuous rather than a batch operation, it pre- 
sents no serious difficulties in the way of equipment 
requirements. The process was, therefore, put into 
pilot plant operation where it produced ethylenedia- 
mine in 70% overall yield.^®’^^ 


£;0XFfDKyTiAr-rf1 


14 


PREPARATION OF HIGH EXPLOSIVES 


It will be recalled that two methods had been stud- 
ied earlier for converting ethylenediamine to ethyl- 
eneurea : the reaction with urea, and the reaction with 
carbon dioxide. The former had been selected as the 
more satisfactory. Since that time further work on 
the ethylenediamine-carhon dioxide reaction, done by 
the Ralph L. Evans Associates under contract with the 
Ordnance Department, had shown that this reaction 
could compete favorably with the ethylenediamine- 
urea process. A pilot plant study of the ethylenedia- 
mine-carhon dioxide reaction was made, and operating 
conditions were worked out whereby this reaction be- 
came the most satisfactory one for the preparation 
of ethyleneurea.^'^*^^ 

All the work described so far can be summarized as 
leading to the following preferred total synthesis of 
Haleite : 


011,0 + HON 

IlOCH^CN +NH 3 

TT2NCH2CN + 2 H, 


> ITOCHoON 

> H^NCH^CN + H^O 

> TT2NCH2CH2NH2 


OTENH^ 

CH^NH 

^co 

CTf^NH 

Cir^NNOj 

^CO 

CH^NNO^ 


+ C0, 


+ 3 HN 03 


+ ICO 




CHo-NII 

^C0 + H,0 
OH,-NH 


OII^NNO^ 



p CO + 2 H ,0 

H 2 NNO 2 

II 2 NHNO, 

+ 00, 

H 2 NHNO, 


Taking advantage of improvements in the nitration 
of ethyleneurea, achieved by using nitric acid alone 
instead of mixed acid,^*^ this synthesis permits the 
preparation of Haleite at a cost of about 30 cents 
per pound. 

In addition to the work described up to this time, 
Division 8 supported one laboratory investigation of 
an entirely different synthesis of ethylenediamine. 
ddie National Research Council in the fall of 1941 
canvassed chemists in this country for suggestions for 
new syntheses of ethylenediamine. Seventeen differ- 
ent methods were suggested, and the chemists who 
pro|)osed them did some preliminary work on a vol- 
unteer basis. One proposed method — the addition of 
nitrogen dioxide to ethylene followed l)y reduction 
of the addition product, 1 , 2 -dinitroethane, to ethyl- 
enediamine — was considered to be of sufficient inter- 


est to merit study by Division 8 . The study showed 
that the addition of nitrogen dioxide to ethylene gave 
only a moderate amount of material reducible to 
ethylenediamine, and that the addition reaction would 
be cumbersome and hazardous to apply to large-scale 
operation.^*'®® 

Finally, in view of the important results obtained 
in the study of the crystallography of RDX and re- 
lated compounds (see Section 1 . 2 ), a comparable 
study was made of Haleite. No polymor])hs were 
found, but information of importance in securing 
pellets of high density was obtained."’^ 

14 DINA*' 

About September 1942 it was discovered in Canada 
that the conversion of a secondary amine nitrate to 
the corresponding nitramine (the Bamberger reac- 
tion) takes place efficiently in the presence of chloride 
ion. This discovery made it possible to prepare bis- 
+nitroxyethylnitramine, DINA,i from diethanol- 
amine, nitric acid, acetic anhydride, and a trace of an 
ionic chloride. The preparation of DINA was inves- 
tigated on a pilot scale in Canada and extensive tests 
of its properties as a high explosive were made in 
Canada and in this country. The low melting point, 
relative chemical instability and sensitivity to impact 
under certain conditions militated against serious 
consideration of DINA as a high explosive in spite 
of its excellent power, but it became apparent by the 
middle of 1943 that this explosive showed great prom- 
ise as an ingredient of propellants. A discussion of the 
use of DINA in gun propellants of superior qualities 
is given under Albanite (Section 6.7); the present 
section deals exclusively with the preparation of 
DINA itself. 

The preparation of DINA^ by nitration of diethan- 
olamine may be carried out by a two-step or a one- 
step procedure. In the two-step procedure diethanola- 
mine is slowly added to a slight excess of concen- 
trated nitric acid; the resulting solution, which con- 
sists of diethanolamine trinitrate (and some lower 
nitrates of diethanolamine) dissolved in nitric acid, 
is then fed slowly into a slight excess of acetic anhy- 

*'This section is based on a summary prepared by S. R. 
Aspinall. 

‘Key references to the properties of DINA as a high explo- 
sive are given in reference 52. 

H^he complete record of the investigations on the preparation 
of DINA and the associated problems referred to later in this 
section is to be found in references 53-58. 


iS^nA 


DINA 


15 


dritle containing catalytic amounts of chloride ion. 
The nitration mixture is drowned, the precipitated 
1)1 XA removed by filtration and washed with water. 
In the one-step nitration the appropriate amounts of 
diethanolamine and nitric acid are fed simultaneously 
(with a nitric acid lead) into acetic aidiydride con- 
taining chloride ion. After completion of the reaction 
the mixture is drowned and treated as before. Because 
of the advantages of the one-step nitration from the 
standpoints of simplicity of operation and economy of 
equipment and because results obtained with it were 
at least as good as those from the two-step procedure, 
only the one-step process was evaluated on a pilot 
scale. 

It is necessary to purify the crude crystalline DINA 
obtained by either process, since it contains residual 
acidity and appreciable amounts of the corresponding 
nitrosamine which lower the stability of the product. 
The purification procedure consists essentially of 
treating DINA with hot water with vigorous agita- 
tion. This treatment results in the destruction of the 
nitrosamine, which is very unstable at the tempera- 
tures encountered, and the extraction of the residual 
acid into the aqueous phase. The molten pure DINA 
resulting from this treatment is allowed to settle and 
is drawn off to he crystallized under cold water or 
from an appropriate solvent. However, because of the 
extreme sensitivity of DINA under certain conditions, 
especially when molten,^^ the purification of DINA 
in quantity as outlined above was not looked upon 
with favor. Therefore, on a pilot scale the crude crys- 
talline DINA was mixed with dibntyl phthalate and 
centralite in the ratio 88.5:10:1.5, and the resulting 
mixture heated with hot water as before. The aqueous 
layer was neutralized to destroy acidity extracted from 
the DINA, and the DINA-dibntyl phthalate-centralite 
mixture (called DDP) allowed to settle, after which it 
was drawn off into small drums where it solidified to a 
superficially dry cast. This modification in purification 
was permissible because dibutyl phthalate and central- 
ite are ingredients of Albanite, into which the DINA 
was converted, and offered great advantages from the 
standpoint of production and storage because of the 
strong phlegmatizing action of the di butyl phthalate 
and the stabilizing action of the centralite. 

The waste acid filtered from the crude DINA con- 
sists of 30% acetic acid containing small amounts of 
nitric acid, hydrochloric acid, DINA, and organic by- 
products arising from diethanolamine and the impu- 
rities present in it (chiefly mono- and triethanola- 
mines). The waste acid is simmered to hydrolyze 


organic nitrates and is partially neutralized with 
caustic to fix the mineral acids. The waste thus treated 
may be extracted continuously with isopropyl or 
ethyl ether and the extract fractionated to yield ni- 
trate- and chloride-free glacial acetic acid suitable for 
conversion to acetic anhydride. Alternatively the sim- 
mered waste may be distilled to yield chloride- and 
nitrate-free 30% acetic acid which is then distilled 
azeotropically to give glacial acetic acid suitable for 
conversion to acetic anhydride. 

A number of problems associated with the DINA 
process were investigated. The results are mentioned 
briefly in the following paragraphs. 

Quality of Raw Materials 

A method was developed for the analysis of dietha- 
nolamine. Adequate methods for analyzing nitric acid 
and acetic anhydride were already known. These 
methods are useful for plant control, but are not 
vitally important to the process, since it was shown 
that the yield and quality of DINA were as satisfac- 
tory with standard commercial materials as with 
specially purified ones. 

Catalyst 

Many materials have been evaluated as catalysts for 
the nitration, but none worked so well as chloride ion. 
Hydrogen chloride is favored for plant use because of 
its cheapness and the fact that no metal is introduced 
into the reaction. 

An attempt was made to demonstrate the exact 
mode by which chloride ion functions as a catalyst, 
but no conclusive results were obtained. 

By-Products 

A study was made of the preparation and properties 
of the possible by-products in the DINA synthesis. 
The most important are those arising from diethanola- 
mine and consist of the nitrosamine analog of DINA, 
(?n*s-^-nitroxyethylnitrosamine), and the analogs of 
DINA in which one or more of the nitro groups are 
replaced by acetyl groups. 

The nitrosamine occurs in crude DINA, but it is 
eliminated in the purification with hot water, since 
the rate of hydrolysis of the nitrosamine to water- 
soluble products is extremely rapid as compared to 
the rate of hydrolysis of DINA. 

The mixed nitro-acetyl derivatives of diethanola- 
mine have never been positively demonstrated to be 
present in crude DINA. Certain of these compounds 
undergo rearrangement in the presence of water to 


froNf'i i)iTvn.\ii*i 


16 


PREPARATION OF HIGH EXPLOSIVES 


give water-soluble ammonium nitrate derivatives. The 
following equation is illustrative. 

O2NOCH2CH2 \ 

^NCOCHg -f H2O — ^ 
O2NOCII2CIT2 / 

CHgCO^CH^CH^ \ 

>nh;no3 

O2NOCH2CH2 / 

Certain other of these compounds, if formed at all, 
are sufficiently soluble or unstable in the waste acid 
that they do not occur in crude DINA. That these 
mixed nitro-acetyl derivatives are formed initially in 
the reaction is evidenced by the fact that yields of 
DINA from diethanolamine are less than those from 
&i5-(^-nitroxyethyl) ammonium nitrate and also by 
the fact that certain of the compounds or their degra- 
dation products are found in the waste acid. 

Miscellaneous 

Many variations of the hot-water treatment were 
tried, including the addition of various reagents which 
might improve the stability of refined DINA. The 
only additive which accomplished an improvement in 
stability and which was acceptable from the stand- 
point of powder manufacture was centralite. 

Chromatography has been used to prepare very pure 
samples of DINA. It was shown that DINA stabilized 
by the usual methods contains extremely small quan- 
tities of impurities, and that such DINA is as stable 
as judged by accepted stability tests as chromato- 
graphically pure DINA. 

Extensive data were obtained on the solubility and 
ciystallographic properties of DINA and on the phase 
behavior of the system DINA-centralite. Absorption 
spectra of DINA and related compounds have been 
measured ; the data obtained have been useful in eval- 
uating the quality of the nitration product. 

15 MISCELLANEOUS NITRAMIDES, 
NITRAMINES, AND NITRAMINE- 
NITRATE ESTERS’^ 

The excellent explosive properties of the cyclic ni- 
tramine DDX prompted an investigation of a wide 
variety of compounds containing the NNOg group. 
In part this work had as its object the preparation of 
nitramines which might be useful as explosives; in 
part it was intended as an exploration of the chemical 
l)ehavior of compounds containing the NNOg group. 

^This section has been constructed from information fur- 
nished by A. T. Blomquist. 


Nitramides, nitramines, and compounds containing 
both nitramine and nitrate ester groups were studied. 
The most important compounds, Haleite, a high ex- 
plosive, and DINA, an explosive plasticizer for gun 
propellants, have been discussed in Sections 1.3 and 
1.4 respectively; the remaining compounds are dis- 
cussed in the paragraphs which follow. 

• Nitramides 

Nitramides have been prepared by direct nitration 
of the following classes of compounds: hydantoins, 
diketopiperazines,^'’® glycolurils,^®*^^ melamine and its 
triacetyl derivative,®^’®^ N-substituted oxamides,®^'®® 
N-substituted glycolamides, substituted ureas, hydan- 
toic acid derivatives, and sulfamides. Attempts to 
prepare nitro derivatives of hexahydro-s-triazinones 
and 2-hydroxy ethyl) urea were unsuccessful. 

The nitramides as a class were found to be unsuit- 
able for use as military explosives. Their stability to- 
ward moisture and heat was inadequate. The nitro 
derivatives of the hydantoins and diketopiperazines 
are markedly hygroscopic. 

Nitramines 

Both primary and secondary nitramines were pre- 
pared and examined. Preparation of primary nitra- 
mines usually involves a procedure developed by 
Franchimont and Klobbie.®® 

ClCO,C,H. ^ RNHCOjCJI, HNOv 

RN(N02)C02Cjr5 UNHNO 2 

Preparation of secondary nitramines either involves 
the alkylation of primary nitramines or the catalyzed 
dehydration of secondary amine nitrates.®^ 

R2NH2NO3 AtoO + Cl-^ R^NNO, 

Among the simple aliphatic nitramines prepared 
were a number of nitramino analogs of well-known 
nitrate ester explosives : 1,2-dinitraminopropane, 
1,2,3-trinitraminopropane, and pentaerythrityl tetra- 
nitramine, the nitramine analogs of propylene glycol 
dinitrate, nitroglycerin, and PETN.®^’®® From the 
studies of these and other related nitramines it 
may be concluded that they, in comparison with the 
nitrate esters, are more stable toward heat, less sensi- 
tive to impact, somewhat less powerful, much higher 
melting, and much more difficult to prepare. 

Details of the preparation, properties, and reactions 
of the various nitramines are to be found in the ref- 


ALIPHATIC AND AROMATIC NITRO COMPOUNDS 


17 


ereiices already cited. Only three other lines of ac- 
tivity can be mentioned in detail here. 

Attempts to prepare polynitramines from diethyl- 
enetriamine, H^NCH^CH^kHCH^CH^ISrH^ and tri- 
ethylenetetramine, H 2 NCH 2 CH 2 NHCH 2 CH 2 NHCH 2 - 
CHoNHg, were only partially successful. 

Studies of the ultraviolet absorption spectra of 
several primary nitramines and their salts and of 
the isomers, trimethylolmethylnitramine and N-tri- 
methylolmethyl-N-nitrosohydroxylamine, aided in 
proving that the product obtained from acetone by the 
Traube reaction was not methylenedinitramine,^ as it 
had long been believed to be, but was, instead, methyl- 
ene-&is-nitrosohydroxylamine.^^ 

Preliminary studies were made of N-halogenated 
derivatives of primary aliphatic nitramines. The com- 
pounds prepared were thermally unstable and quite 
sensitive to impact.®® 

1.5.3 Nitramine-Nitrate Esters 

As part of the work on explosive plasticizers for 
Albanite powder (see Section 6.7), a number of nitra- 
mine-nitrate esters were prepared and evaluated. 
Those containing a primary nitramino group, 
(NENA, O 2 NOCH 2 CH 2 NHNO 2 , is an example) 
were prepared from aminoalcohols by the procedure 
outlined above for primary nitramines. Those con- 
taining one or more secondary nitramino groups 
were prepared either by the catalytic dehydration of 
the amine nitrates of the appropriate aminoalcohols or 
by alkylating a primary nitramine, such as ethylene- 
dinitramine, with an alkylene oxide.^® 

The two last-named procedures led to three groups 
of nitramine-nitrate esters 

1. DINA analogs, (02N0CH(R)CH2)2NlSr02. 

2. N-Alkyl analogs of NENA, (02N0CII(R)CH2- 

N(R)N02. 

3. Compounds derived from ethylenedinitramine. 

NO2 NO2 

I I 

OjNOCH (R) CHjNCHXH^NCHjCH (R) ONO^ 

Of the nitramine-nitrate esters prepared in these ways, 
DINA, butylNENA, cyclohexylNENA, and, perhaps, 
Z>fs(2-nitroxyethyl) ethylenedinitramine have shown 
the most promise as explosive plasticizers. The nitra- 
mine-nitrate esters as a class are not so satisfactory 
as RDX or Ilaleite for use as high explosives. 

^The true methylenedinitramine had been obtained in an 
entirely different way by British workers.'^^ 


16 ALIPHATIC AND AROMATIC 

NITRO COMPOUNDS"^ 

^ ^ ^ Aliphatic Nitro Compounds 

Recent industrial developments have made several 
simple nitroparaffins commercially available. These 
volatile, liquid nitroparaffins are not themselves suit- 
able as military high explosives. They have been used, 
however, as starting materials for the preparation of 
more complex polynitroparaffins which might reason- 
ably be expected to have military applications. In this 
synthetic program a number of previously known poly- 
nitroparaffins were made by improved techniques and 
some new compounds were made by well-established 
methods.^ None of the compounds prepared was of 
immediate interest. Those compounds which were 
promising could not be prepared by a practical pro- 
cedure. Those compounds which could be prepared 
with any facility were disqualified as high explosives 
for one or more of the following reasons: (1) low 
melting point or high vapor pressure, (2) insufficient 
power, (3) lack of stability, (4) acidity due to the 
presence of a-hydrogen atoms. 

Much time was spent on unsuccessful efforts to 
synthesize tetranitroneopentane, 0(0142^02)4, and 
2, 2, 5, 5-tetranitrohexane, OH 3 O (NO 2 ) 2 CH 2 OH 2 O- 
(N02)2CIl3. From the difficulties encountered in 
these attempts and in less extensive efforts on related 
compounds, it is a reasonable prediction that the de- 
velopment of satisfactory syntheses of polynitroparaf- 
fins suitable for use as military high explosives will 
he a long-term project dependent for its success on a 
very considerable increase in our knowledge of the 
chemistry of the simple nitroparaffins and their de- 
rivatives. 

Three simple polynitroparaffins have received some 
attention in the laboratory. Nitroform (trinitrometh- 
ane) was prepared by procedures described in the 
literature, and some of its reactions were explored in 
preliminary fashion ; the condensation with formalde- 
hyde to furnish trinitroethanol was successful.'^® Tet- 
ranitromethane was also prepared hy methods avail- 
able in the open literature.'^® The preparation of 1,2- 
dinitroethane from ethylene and nitrogen dioxide was 
investigated rather carefully; the maximum conver- 
sion was 35%. 1,2-Dinitroethane was of interest not 

"*This section is constructed from material furnished by S. 
R. Aspinall, Marvin Carmack, and Frank H. Westheimer. 

'^The reader is referred to the original reports for the names 
of the large number of compounds prepared.'^^d'^ 


i'dXffnRVTtOl 


18 


PREPARATION OF HIGH EXPLOSIVES 


in itself but as an intermediate in the preparation of 
Haleite (see Section 1.3). 

Nitroethylene polymer was also prepared (see Sec- 
tion 1.8). Its explosive properties are very inferior. 

1.6.2 Aromatic Nitro Compounds 

Work with the aromatic nitro compounds has dealt 
both with preparative procedures for individual com- 
pounds and ■ with the mechanism of the preparative 
reactions. 

Attempts to improve the preparation of trinitro- 
benzene (TNB) did not lead to useful results. The 
synthesis of TNB from furoic acid, via mucobromic 
acid and nitromalonic aldehyde, was re-examined. Al- 
though the yield in the first reaction was improved, 
the yields in the second and third reactions could not 
be increased and the overall yield was only about 5%.° 
A successful laboratory procedure was developed for 
converting picryl chloride to TNB by reducing the 
chloride in aqueous alcoholic solution with copper 
powder. The yield of TNB is 77^, and the copper 
can be recovered and used again. An alternative pro- 
cedure, the hydrolysis of trinitrobenzenesulfonic acid, 
did not work.®^ 

A process for the nitration of benzene and toluene 
in the absence of sulfuric acid was examined. In this 
process, water initially present or formed in the reac- 
tion is removed by azeotropic distillation. The econ- 
omies claimed for the process were not realized in 
the trials.*^ Another process envisaged for the nitra- 
tion of aromatic compounds in the absence of sulfuric 
acid involved the use of concentrated perchloric acid 
as the reaction medium. Work toward this end was 
limited to an attempt to devise an analytical method 
for determining the extent of nitration of samples of 
reactants sufficiently small to permit the safe use of 
concentrated perchloric acid. A micro-Kjeldahl pro- 
cedure gave satisfactory results with mixtures of 
known composition but failed when it was applied 
to rate studies.*^ A study of the kinetics of nitration 
of nitrobenzene, dinitroxylene, dinitromesitylene, and 
other aromatic nitro compounds dissolved in sulfuric 
acid showed that the reaction between nitric acid and 
nitro compound was second order, and that the rate 
constant depended on the sulfuric acid concentra- 
tion.®^ This constant is a maximum for solutions con- 
taining about 90% sulfuric acid ; it is only one-sixth 
as great in 100% sulfuric acid and less than one- 
thousandth as great in 80% acid. Added materials, 

^Unsuccessful attempts to prepare TNB from /3-nitroethanol 
and from nitroacetaldoxime are described in reference 80. 


such as sodium bisulfate, affect the rate in the way 
which would be predicted from their effect on the 
acidity of the medium. Large quantities of nitric 
acid affect the acidity of the medium so as to make it 
approach the optimum for nitration. The position of 
the maximum rate is only slightly dependent on the 
temperature. The introduction of a nitro group into 
the aromatic nucleus decreases the rate of nitration 
by a factor of about 10®. 

Presumably the mechanism of nitration involves 
a reaction between the substance to be nitrated and 
the NOt ion. It has been shown by an indicator 
method that the tremendous difference in nitration 
rates when 80 and 90% sulfuric acid solutions are 
used is due to the change in concentration of the ionic 
intermediate, NOj. Since the formation of NOj 
from the nitric acid controls the nitration rate, the 
maximum rate should and does occur at the same 
concentration of sulfuric acid in the nitration of 
nitrobenzene, ^,6-dinitro-l,3-xylene, and dinitrome- 
sitylene. 

Solubility effects restrict somewhat the application 
of these conclusions to the large-scale preparations 
of aromatic nitro compounds. 

The conclusions reached in the report Just reviewed 
were confirmed by a study of the preparation of trini- 
troethylbenzene (TNEB).®® Ethylbenzene was ni- 
trated quantitatively to dinitroethylbenzene. The rate 
of nitration of dinitroethylbenzene to TNEB is af- 
fected by the same factors which were found to he 
operative in the analogous aromatic nitrations de- 
scribed above. The maximum yield of TNEB was 
80%. The principal cause of loss was oxidation of 
dinitroethylbenzene by nitric acid. No method of de- 
creasing this loss was discovered. 

The preparation of the polynitronaphthalenes was 
studied in some detail because of the availability of 
naphthalene as a raw material. If it were possible to 
nitrate naphthalene economically to furnish explosives 
comparable with TNT, these products would consti- 
tute a welcome wartime addition to the supply of high 
explosives. Since the power of 1,3,8-trinitronaphtha- 
lene in the ballistic mortar is only 83% of that of 
TNT, while the power of 1,3,6,8-tetranitronaphtha- 
lene is 101% of that of TNT, it is essential to be able 
to nitrate naphthalene to tetranitro derivatives if the 
products are to be useful. 

Methods were first developed for the preparation 
of pure trinitronaphthalenes, then the nitration of the 
pure trinitro compounds was studied. With the infor- 
mation thus obtained, procedures were developed for 


ALIPHATIC AND AROMATIC NITRO COMPOUNDS 


19 


preparing tetranitroiiaplitlialeiies from 1-nitronapli- 
thalcne, mixtures of diiiitronai)lithalenes, or mixtures 
of triiiitrouaplithaleues. These procedures unfortu- 
nately do not hold much practical promise^ for the 
yield of tetrauitroiiaphthaleues never exceeds 50%, 
and ail excess of 3 to 4 moles of nitric acid over the 
amouiit theoretically necessary is always consumed 
in the process. The two disadvantages are apparently 
causally connected : the low yield of tetranitronaph- 
thalenes is a result of loss by oxidation reactions, and 
the high consumption of nitric acid is a result of its 
use as the oxidizing agent in these reactions. 

The following preparative procedures were devel- 
oped. The yield is given in parentheses following the 
name of the product. 

Xaphthalene to 1-nitronaphthalene (94 to 98%). 

1 - Xitronaphthalene to 1, 5 - dinitronaphthalene 
(30%) and 1,8-dinitronaphthalene (30%); yield of 
mixed dinitroiiaphthalenes, 95%. 

1 - Xitronaphthalene to 1,3,8 - trinitronaphthalene 
(33%); yield of mixed trinitronaphthalenes, 94%. 

1.5- Dinitronaphthalene to 1,4,5-trinitronaphthalene 
(41%) ; yield of mixed trinitronaphthalenes, 94%. 

1,5 - Dinitronaphthalene to 1,4,5,8-tetranitronaph- 
thalene (34%) and 1,3,5,8 - tetranitronaphthalene 
(14%). 

1,3,8-Trinitronaphthalene to 1,3,6,8-tetranitronaph- 
thalene (50%) and 1,3,5,8 - tetranitronaphthalene 
(3%). 

1.4.5- Trinitronaphthalene to 1,4,5,8-tetranitronaph- 
thalene (30%) and 1,3,5,8-tetranitronaphthalene 
(13%). 

l-Xitronaphthalene to a mixture of tetranitronaph- 
thalenes (50%). 

Methods of separation and analysis of the nitration 
products were worked out; some addition compounds 
of 1,3,8-tritronaphthalene, and 1,3,5,8- and 1,3, 6,8- 
tetranitronaphthalene are described ; and the behavior 
of 1,8-dinitronaphthalene, 1,3,8-trinitronaphthalene, 
and l,3,G,8-tetranitronaphthalene toward fuming sul- 
furic acid is reported.®*^ 

1.6.3 Oxynitration of Benzene to Picric Acid 

The direct conversion of benzene to picric acid,^ 
usually referred to as the oxynitration of benzene, has 
been studied both as a preparative procedure and with 
respect to the mechanism of the reactions involved. 
The work was undertaken in the fall of 1942 when it 

Pin practice the principal product of the process is either 
dinitrophenol or picric acid according to the experimental 
conditions employed. 


appeared that there might he a shortage of phenol for 
the preparation of })icric acid and, from it, ammonium 
picrate.‘‘ The work was successful in that procedures 
were developed for the direct conversion of benzene 
to picric acid which are at least as efficient as, and 
probably more efficient than, either the nitration of 
phenol or the indirect preparation of picric acid from 
benzene via chlorobenzene; and the mechanism of 
the reactions involved is well understood. The process 
was never put into commercial operation, as the 
phenol shortage which had been feared did not occur. 
However, the process has been developed to the extent 
that it must be considered as a serious potential rival 
to the alternative processes and, before any expansion 
of dinitrophenol on picric acid production is under- 
taken, the oxynitration process should be evaluated 
in the pilot plant. 

The oxynitration of benzene and other aromatic 
hydrocarbons was discovered and patented by Woltfeii- 
stein and Bbters in 1906.^^ Their procedure involved 
the treatment of benzene with aqueous nitric acid 
containing mercuric nitrate. Although much attention 
has been devoted to the oxynitration procedure almost 
since its original disclosure, it was only with the work 
of Division 8 that the method was developed to the 
point where it could compete with alternative proc- 
esses. In describing this work we shall, first, discuss 
the preparative procedures and then discuss the mech- 
anism of the reactions involved.®® 

A critical study was made of the effects of the nu- 
merous variables, including acid strength, rate of 
addition of benzene (effective benzene concentration), 
concentration of mercuric nitrate, temperature, time, 
effect of nitrogen oxides, and effects of other added 
substances. 

The two variables of greatest importance are the 
concentration of nitric acid and the effective concen- 
tration of benzene (that is, benzene dissolved in the 
oxynitration solution). The optimal concentration of 
nitric acid is in the range 10.4 to 11.6 4/ (or the 
equivalent of 50 to 55% by weight for pure acid). 
The acid concentration greatly influences the overall 
rate of reaction; below 10.4 M the rate falls off rap- 
idly, while above 10.4 M the rates of both the oxyni- 
tration reaction and various side reactions, such as di- 
rect nitration, increase rapidly. The range mentioned 
above seems in general to give the lowest proportion of 

^Earlier, a Canadians'^ procedure for the oxynitration of 
benzene by treatment with nitric acid together with mercuric, 
manganese, and aluminum nitrates was checked. The yield of 
picric acid was 50%. ss 


(£oXttwxttaT5 


20 


PREPARATION OF HIGH EXPLOSIVES 


Jieiitral iiitro compoiiiuKs to iiitropheiiols with, at the 
same time, an adequate rate ot' oxynitratioii. It is 
essential to fortify the oxynitratioii solution at fre- 
quent intervals or, preferably, continnonsly. Fortifica- 
tion with 95 to 98^ nitric acid is particularly advan- 
tageous since it results in a smaller increase in reac- 
tion volume than does the use of more dilute acid; 
the use of absolute nitric acid does not require any 
special modifications of procedure except avoidance 
of direct contact of the strong acid with liquid 
benzene. 

The effective benzene concentration is probably the 
most critical variable affecting the proportion of neu- 
tral nitro componnds to iiitropheiiols and also the 
formation of colored by-products. Vigorous agitation 
of excess benzene, keeping the oxynitratioii solution 
nearly saturated with benzene, leads to poor yields of 
Iiitropheiiols, high yields of nitrobenzene and dinitro- 
henzene, and the formation of highly colored impu- 
rities Avhich are difficult to remove from the products. 
In batch runs it was found that the results differ 
greatly if all the benzene is added in one portion or 
if it is added slowly over a considerable period. The 
yields of iiitropheiiols increase sharply, then level 
off and become constant as the time of dropwise addi- 
tion of benzene is increased. The addition of small 
sings of benzene at regular intervals was found to he 
as satisfactory as continnons dropwise addition, pro- 
vided the rate of addition is carefully adjusted so as 
not to exceed the optininm rate of oxynitratioii for the 
particular set of conditions. In a vigorously stirred 
solution the benzene concentration is certainly deter- 
mined very largely by the rate of conversion of ben- 
zene to intermediates; in batch runs, therefore, the 
rate of addition of the benzene is the important vari- 
able to control, and an excess of imdissolved benzene 
must he avoided. 

In runs with moderate stirring and an excess of 
benzene phase, the degree of agitation becomes a vari- 
able, since it partially determines the rate at which 
benzene dissolves in the oxynitratioii solution. The 
mere presence of a separate benzene phase is not in 
itself deleterious except when the dispersion of the 
benzene phase through the aqueous acid solution is 
such that the oxynitratioii solution is kept nearly 
saturated at all times. Good yields have been obtained 
in runs in which a benzene phase floated upon an 
unstirred reaction mixture. In the continnons extrac- 
tion process to be described later a considerable 
amount of liquid benzene is always present but is 
dispersed in the form of droplets which rise rapidly 


through ihe oxynitrafion solution, dissolving to some 
extent hut not necessarily rapidly enough to saturate 
the solution. When benzene is injected into an un- 
stirred oxynitratioii solution by a device such as a 
fritted disk or through capillary tubes, the size of the 
dispersed droplets as well as the rate of addition of 
benzene become important variables affecting the 
yields and ratios of products. 

The concentration of mercuric nitrate catalyst af- 
fects the rate of oxynitratioii, the rate being approxi- 
mately proportional to the catalyst concentration when 
other factors are constant. Over a fairly wide range, 
the catalyst concentration does not appear to be a 
critical variable. Concentrations of 0.37 to 0.5 mole of 
mercuric nitrate per liter of oxynitratioii solution have 
been found to give satisfactory results in most cases. 

The reaction temperature does not appear to be a 
critical variable except as- it affects the relative rates 
of the various reactions. A higher proportion of nitro- 
benzene may be formed at higher temperatures. The 
overall rate of oxynitratioii increases by a factor of 
about 1.8 to 2 for each 10 C rise in temperature. At 
the boiling point of the oxynitratioii mixture, the 
nitration of DNP to PA gives only about an 80% 
yield ; it is therefore obviously an advantage to isolate 
DNP under relatively mild oxynitratioii conditions, 
then to nitrate that product separately in a nitric-snl- 
fnric acid mixture when the yield of VA exceeds 95%. 

The presence of some nitrogen oxides is essential 
for the occurrence of the oxynitratioii reaction. If 
oxides of nitrogen are destroyed or jirevented from 
forming by the addition of urea, the benzene is simply 
converted to phenylmercuric nitrate and polyniercn- 
rated derivatives of benzene. On the other hand, a con- 
centration of nitrogen oxides approaching saturation 
is very unfavorable and leads to poor yields of nitro- 
phenols and the formation of dark colored by-prod- 
ncts. The nitrogen oxide level equivalent to the pres- 
ence of 0.05 M nitrons acid in 50% acid is estimated 
to be approximately the optimal concentration for the 
oxynitratioii reaction. Because of the experimental 
difficulties, little effort has been made to control this 
variable; it would appear to be a promising point for 
further investigation. 

The use of aliiniinnm nitrate in the low concentra- 
tions recommended by the Canadian investigators does 
not appear to have any influence on the oxynitratioii 
process. 

Manganous nitrate, recommended by the Canadian 
investigators as a catalyst for the oxynitratioii and 
also for the destructive oxidation of oxalic acid, has 


ALIPHATIC AND AROMATIC NITRO COMPOUNDS 


21 


little ell'eet in low eoiieeiitratious. In eoncentrations 
of O.o M or higher it has a definite ('atalytio action 
on the rate of formation of DNP and the oxidation 
of oxalic acid ; unfortunately, it also seems to catalyze 
the formation of nitrobenzene and the nitration of 
DXP to PA. 


P K KPA 1{ A'rOK Y PUOCEDUII KS 

Four laboratory procedures, two batch and two con- 
tinuous, have been developed for the ox 3 mitration. In 
the first batch process®^ one liter of solution is used 
for the oxynitration of approximately 70 g of benzene. 
The solution is originally 10.G5 M in nitric acid and 
0.37 M in mercuric nitrate. Approximately 120 ml 
of 1)8^ nitric acid is used to fortify the solution. The 
reaction time is 6 hours at 50 C. The benzene balance 
for such a run is as follows : 


Benzene as dinitroplienol 68.4% 

Benzene as picric acid 4.0% 

Benzene as nitrobenzene 7.8% 

Benzene as o-dinitrobenzene 1-0% 

Benzene as p-dinitrobenzene 0.7% 

Benzene as 2,4,2',4'-tetranitrodiphenylamine 0.5% 
Benzene as carbon dioxide 9.7% 

Benzene as oxalic acid 2.5% 

Benzene not accounted for 5.4% 


72.4% 


These yields were based on the benzene which re- 
mained in the reaction flask. In a typical run about 
7.5% of the benzene introduced was lost by volatiliza- 
tion. This loss can be reduced by more efficient cool- 
ing and by absorbing the volatilized benzene in oxy- 
nitrating solution. The oxynitration solution after 
this reaction can be fortified to its original strength 
and used for a second run ; this fortification and reuse 
can be repeated several times if appropriate methods 
are used to separate the picric acid and dinitroplienol 
from the neutral by-products Avhich accumulate. 

The second batch jiroccss — the batch extraction 
process — differs from the one just described in that, 
at the end of the 6-hour reaction period, a large excess 
of benzene is introduced Avith vigorous stirring. After 
the added benzene has dissolved the reaction products, 
the benzene solution is AvithdraAvn and the aqueous 
solution is used to oxynitrate a fresh charge of ben- 
zene. On the assumption that a constant (predeter- 
mined) AA^ight of benzene remains in the reaction 
after each extraction, it is possil)le to determine the 
yields; they are thus found to be comparal)le Avith 
those in the simple batch procedure described above. 
The process cannot be operated indefinitely Avithout 
adding manganous nitrate to catalyze the oxidation 
of oxalic acid, Av^hich otherAvise accumulates and pre- 
cipitates as mercuric oxalate. When manganous nitrate 


is added it causes a slight iiiciease in the i)roduction 
of nitrobenzene at the exi)euse of the nitrophenols and 
increases the ratio of picric acid to dinitroplienol. In 
a typical run Avith 10.65 M nitric acid, 0.37 M mer- 
curic nitrate, and 0.56 M manganous nitrate, the 
yields were 54.2% of dinitroplienol, 13.9% of picric 
acid, and 10.7% of nitrobenzene. 

The first continuous process, knoAvn as the continu- 
ous solution process, operates on the folloAving cycle. 
The oxynitration solution is saturated Avith benzene by 
vigorous agitation Avith excess benzene at room tem- 
perature; the saturated solution is separated from 
excess benzene and circulated through a heated coil ; 
it is then cooled to room temperature and agitated 
again Avitli benzene, Avhich^extracts the organic prod- 
ucts and resaturates the oxynitration solution. In 
evaluating this process, the rate of formation of dini- 
trophenol per liter of reacting solution in the coil is 
determined; 70 g of dinitroplienol per liter per hour 
is representative performance. 

The second continuous process, the continuous ex- 
traction process, involves the use of a continuous 
liquid-liquid extractor and an excess of benzene to 
remove the reaction products.®^ In steady-state opera- 
tion this process Avill produce nitrophenols at a rate 
equivalent to 31 g of dinitroplienol per liter of oxy- 
nitration solution per hour. The yields of dinitro- 
phenol, picric acid, and nitrobenzene are 44.1%, 
29.2%, and 6.5%, respectively. Higher rates of oxy- 
nitration are possible, but the concentration of man- 
ganous nitrate necessary to bring about oxidation of 
the oxalic acid formed favors both the formation of 
nitrobenzene at the expense of nitrophenols and the 
formation of picric acid from dinitroplienol. 

The most successful apparatus consists of a vertical 
cylindrical reactor equipped Avith funnels, condenser, 
outlet at bottom, and a side-arm near the top through 
Avhich excess benzene containing dissolved reaction 
products can overfloAV into a separate receiver. The 
l)enzene is introduced into the bottom of the reaction 
mixture through a cluster of 22 capillary glass jets 
as a shoAAxr of small droplets Avhich rise through the 
solution. The circulation rate is approximately 200 to 
400 ml per hour; the effectiA^e reaction volume is 
1,350 ml. No stirring of the solution is used other than 
that resulting from the movement of benzene droplets, 
coiiATction currents, and fortifying acid. This is an 
important feature of the process, since the degree of 
dispersion of the benzene throughout the solution de- 
termines the rate at Avhich benzene dissolves, and this 
in turn determines not only the rate of oxynitration 


Ui.XiIDKNTlAQ 


22 


PREPARATION OF HIGH EXPLOSIVES 


but also the })roportions ol‘ procluets ajul hy-produets. 
F'ortilieation with 1)8% nitric acid is continuous 
through a device which dilutes and disperses the 
strong acid before it can come directly into contact 
with liquid benzene. The reaction temperature is 
regulated by means of an external water jacket. 

The benzene droplets rising through the solution 
partially dissolve and react while the remaining drop- 
lets extract reaction products and merge in a layer on 
the top of the acid solution. From the reactor this 
excess benzene overflows into a separate flask known 
as an ‘^evaporator/^ which is heated in an oil bath 
to distil benzene and nitrogen oxides away from the 
reaction products into a second flask called the 
“boiler.’^ The boiler is also^ heated to redistil the ben- 
zene through a condenser back again to the jets 
through which it is reintroduced into the oxynitration 
solution. The “evaporator’’ flask can be replaced with- 
out interrupting the operation of the reactor. 

liKACTiox Mechanisms 

Tlie mechanism of the oxynitration reaction has 
been shown to be the following 


C„H„ + Hg(N03),— ).C„irHoN03 + UXO, (4) 

C3n3HgN03 + ycjrxo + Hg(N03)3 (5) 

The nitrosobenzene formed in reaction (5) is converted 
to mononitrophenol by two different paths. The first, 
reactions (b), (7), and (8), goes through a diazonium 
salt. 

(^,ir,NO + 2N0-~^C,1J,N,N()3 (C) 

C,11,NV\03 + 11,0— + N, + I1N03(7) 

C 3 H 3 OH + IINO 3 O^XC'^H.OH + II 3 O ( 8 ) 

The second, reaction (6), involves oxidation and re- 
arrangement. 

C3II3N0 o^xt'oir.oii (D) 

oxidation and rearrangement 

The nitrophenol, formed either in reaction (8) or 
reaction (9), is then nitrated further. 

O^NC^HjOlI + HNO3 ^1%- 

(()3X)3(VCOii + ICO (10) 

(o.,N)3C„ir30ii + HXO3 

( 03 X) 3 (' 3 H 30 H + Il 30 (11) 

In solutions where the nitrite concentration is high 
and the nitric acid concentration is low, reactions 
(G), (7), and (8) take place; in solutions where the 
nitrite concentration is low and the nitric acid con- 
centration is high, the oxynitration goes ])y way of 


reaction (!)). ddie particular oxides of nitrogen s])eci- 
fied in these reactions may be in error; frequently tlie 
reactions can be balanced on the assuni})tion that moi*e 
than one oxide of nitrogen is the active reagent or 
catalyst. 

The experimental evidence for this mechanism is 
as follows. In the presence of urea, the concentration 
of nitrite in nitric acid is kept low. Under these con- 
ditions, a solution of mercuric nitrate in nitric acid 
converts benzene to the equilibrium mixture (4) con- 
taining phenylmercuric ion. This ion was identified 
by precipitation as phenylmercuric chloride. The equi- 
librium between benzene, mercuric nitrate, phenyl- 
mercuric nitrate, and nitric acid was approached from 
both sides, and the same value of the equilibrium coji- 
stant obtained. Finally, the rate of mercuration of 
benzene by mercuric nitrate in the presence of urea 
was measured in nitric acid of varying concentration ; 
the rate of the mercuration reaction was closely the 
same as the rate of the overall production of dinitro- 
phenol in the oxynitration.^^*^ 

In the absence of urea or, more accurately, in the 
presence of nitrite, phenylmercuric nitrate reacts to 
form nitrosobenzene [equation (5)]. Fart of the evi- 
dence for this step in the mechanism was supplied by 
the isolation of nitrosobenzene from the reaction mix- 
ture of phenylmercuric nitrate and nitrite in nitric 
acid solution.®®'^ 

In dilute nitric acid, nitrosobenzene further reacts 
with nitrite to form pheiiyldiazonium nitrate [equa- 
tion (G)]. The diazonium salt could likewise be pre- 
pared by the action of nitrite on phenylmercuric ni- 
trate [equations (5) and (G)]. This was demonstrated 
by isolating /^-dimethylaminoazobenzene, a coupling 
product of the diazonium salt with dimethylaiiiline, 
in 78% yield. The rate of formation of the diazonium 
salt in dilute nitric acid solution was measured starting 
both from phenylmercuric nitrate and from nitroso- 
henzene. The rate of reaction from the latter com- 
pound followed a simple first-order reaction curve; 
whereas the rate of reaction, starting from the former, 
showed an induction period which could unambigu- 
ously be correlated with a two-step reaction, where both 
steps had approximately the same rate. The identifica- 
tion was definite because the rate of the second step 
[the conversion of nitrosobenzene to the diazonium salt, 
equation (G)] was independently determined. 

In more concentrated nitric acid solution it was no 
longer possible to isolate a good yield of diazonium 
salt, d’he oxynitration nevertheless jiroceeded smooth- 
ly and gave better overall yields than in more dilute 


It uM'l liKN'TI aTV 


NITRATE ESTERS 


23 


solution. SiiK ‘0 identical yields ot' diazoninin salt were 
always obtained from jdieiiylniereiirie nitrate aJid I'rom 
nitrosobeiizene under all experimental eonditions, it 
is very ])robal)le that nitrosobeiizene is formed from 
pbenylmerenric nitrate even in eoneentrated nitric 
aeid solution. On the other hand, in eoneentrated ni- 
trie aeid the yield of 2,4-din itrophenol from ])henyl- 
nierenrie nitrate is greater than from phenyldiazo- 
ninni nitrate, so the latter eannot be an intermediate 
under these eonditions. A rearrangement of nitroso- 
benzene analogous to that of phenylhydroxylamine to 
yj-aminophenol appeared possible. This rearrangement 
would be aeeompanied by or followed by an oxidation. 
That sneh a rearrangement actually occurs was made 
very proliable by studying the reactions of o-nitroso- 
tolnene. In dilute nitric acid in the presence of nitrite 
and mercuric nitrate, this comiionnd forms a diazo- 
ninm salt and is finally converted to 4,()-dinitro-o- 
cresol, in conformity with the predictions of the dia- 
zoninm salt mechanism [equations ( 6 ), (7), ( 8 )]. 
But in more concentrated nitric acid solution, no 
diazoninin salt is formed, and o-nitrosotolnene is con- 
verted in excellent yield to 2,4,G-trinitro-i//-cresol. In 
this reaction, it is apparent that the hydroxyl group 
has taken up a position para (or possibly ortho) to 
the original nitroso group. 



0,N 


CII3 

/\x 


IK) 


NO., 


NO., 


The subsequent nitration of the })artially nitrated 
phenols takes place at rates consistent with the as- 
sumption that they are intermediates in the reaction. 
The presence of certain by-products^®*^ has likewise 
been ex])lained, and is consistent with the mechanism 
advanced. 

A related stndy®^ dealt with the mechanism of ni- 
trite catalyzed nitrations of phenol and the nitro- 
phenols. To this end, the eqnililirinm among II NO.^, 
’ NO 2 , N 2 O 4 , NO, and N 2 O 3 was studied in solu- 
tion by means of a crude spectro])hotonieter (Cole- 
man). N 2 O 3 absorbs heavily in the region around 
(),000 to 7,000 A and around 4,000 A, whereas NO 2 
absorbs only in tbe region around 4,000 to 5,000 A. 
The two oxides of nitrogen can therefore be distin- 
guished, and it is possible to analyze for each in the 
jiresence of the other. The ways in which the concen- 
trations of these compounds vary with change in the 
concentration of gross nitrite (nitrous acid by titra- 


tion) and with tbe concentration of nitric acid were 
determined. It was found that the concentration of 
N 2 O 3 varied roughly as the square, the concentra- 
tion of NO 2 with the square root, of the gross nitrite 
concentration. With increase in the concentration of 
nitric acid at constant gross nitrite concentration, the 
amount of NO 2 increases sharply; the amount of 
N 2 O 3 is less affected. 

Next the rate of nitration of phenol and of the ni- 
trophenols was determined. Iloiighly speaking, the 
rate of nitration of /i-nitrophenol increases 70-fold 
as the nitric acid concentration is increased from 10 
to 60% ; there are similar increases for the other 
phenols studied. The rate of nitration varies roughly 
as the square root of the gross nitrite concentration. 
The effect of change in nitrous and nitric acid con- 
centrations on the rate of nitration parallels the 
affect of these changes on the concentration of NO 2 , 
and it therefore becomes probable that NO 2 is the 
active catalyst in the nitration of phenols. It was also 
noted that the nitration of anisole, catalyzed by oxides 
of nitrogen, resulted in the loss of the methyl group 
to give dinitrophenol as the product. On the basis of 
these facts, a tentative mechanism for the nitration 
of phenols was advanced. 

No explanation was advanced for the considerable 
decomposition which accompanies the mononitration 
of phenol. 

17 NITRATE ESTERS 

Work in this field has been confined to a very few 
substances ;*■ and, with one exception, has dealt with the 
preparation of the alcohols to be nitrated ratber than 
with the preparation of the nitrate esters themselves. 

A survey of the literature showed neither natural 
sources nor preparative methods which could be devel- 
oped in any reasonable time to furnish significant 
amounts of erythritol or its stereoisomers.®® No ex- 
perimental work was done. 

The preparation of anhydroenneaheptitol was in- 
vestigated as the first step in a study of its pentani- 
trate (I). 

(02N0CIT2)2C (TI 2 - 

O 2 NOCH 0 

(02N0CH2)2C CTI 2 

I 

'"Twelve sugar alcohols and glycosides were prepared for the 
determination of their heats of combustion and their behavior 
on nitration, but no further work was done with them.^^ 



21 


PREPARATION OF HIGH EXPLOSIVES 


A ])roct*(lurc was developed wliieli })eriuilted tlie prep- 
aration of anliydroeniieaheptitol in 50 to 57% yield 
from formaldehyde and acetoJie. The reaetion must 
he mil at high dilution, which makes it necessary to 
evaporate a large volume of water in order to isolate 
the product. Further, only about one-half of the prod- 
uct can he isolated as such; the remainder is obtained 
by converting the material to its dibenzylidene deriva- 
tive and then hydrolyzing this derivative.®^ No further 
work was done with anliydroeniieaheptitol, but the 
material obtained in the preparative study was ni- 
trated and the explosive properties of the nitrate were 
determined. Anhydroenneaheptitol peiitanitrate has 
an imjiact sensitivity comparable Avith that of EDX ; 
its poAver in the ballistic mortar is 157% of that of 
TNT, or about inidAvay betAveen tetryl and IvDX.®^ 
A study of the preparation of pentaerythritol, PE, 
from formaldehyde and acetaldehyde shoAA^ed that the 
yield of crude PE is about 10% greater Avhen the 
aldehydes are added to an aqueous suspension of 
calcium hydroxide, than Avhen lime is added to the 
aldehydes. The preferred procedure furnishes a 66 to 
68% yield of crude PE; this product assays about 
86% PE, so that the yield of pure PE is about 58%. 
A number of promoters, Avhich have been recom- 
mended for the reaction, Avere tried and found to be 
of no value. A bibliography and description of the 
methods of preparation of PE reported in the litera- 
ture are included in the report of the Avork.®® 

A later study of the same reaction continued the 
observation that addition of the aldehydes to the lime 
gaA'e better yields of PE than did addition of lime 
to the aldehydes; hoAA'eA'er, the latter order of addi- 
tion gave a PE of better quality. Acetaldehyde can be 
replaced by crotonaldehyde Avithout lowering the qual- 
ity of the l^E, but Avith a loss in yield ; acetaldehyde 
can he replaced by aldol Avithont loAvering either the 
quality or the yield. Aldol is more convenient to use 
than acetaldehyde. Only slight differences in yield 
and quality of PE resulted Avhen paraformaldehyde 
Avas substituted for formalin. Paraformaldehyde ab- 
sorbs heat on depolymerization and this makes the 
control of temperature easier. Hy adding lime to the 
mixture of aldehydes, a 60 to 67% yield of PE AA’hich 
is 02 to 05% pure is obtained ; by adding the alde- 
hydes to the lime a 65 to 68% yield of PE Avhich is 
87 to 88% pure is obtained. The importance of the 
second exothermic reaction, ])resumahly the destruc- 
tion of the excess formaldehyde, is stressed. A detailed 
procedure for the assay of crude PE hy means of its 
benzylidene derivative is described.^®® 


The single nitnite ester Avhose pi’e[)aration has l)ee]i 
studied in detail is Fivonite [2,2,5,5-tetramethylolcy- 
clopentanone tetranitrate (111)], a substance de- 
scribed in the chemical journals and in patents before 
the Avar.^®^'^®^ The interest of Division 8 in this mate- 
rial Avas twofold : as a high explosive Avhich might 
replace TNT in mixed explosives analogous to Com- 
position B, Ednatol, and Pentolite, and as a substitute 
for nitroglycerin in double-base poAvders. 

Fivonite is a solid melting at 68 C ; it possesses sat- 
isfactory stability; its impact sensitivity is betAveen 
those of PDX and tetryl; its poAver is comparable Avith 
that of tetryl; and the starting material for its syn- 
thesis is not in demand for the preparation of either 
TNT or synthetic rubber. Tests on mixtures of Fivo- 
nite Avitli ItDX, Haleite, and PETN shoAved that these 
mixtures Avere more ])OAverful and more brisant than 
the corresponding mixtures made Avith TNT, but this 
improA^ed performance Avas offset by increased sensi- 
tiveness.^®'* The use of FiA'onite in place of nitroglyc- 
erine as a plasticizer for nitrocellulose in double-base 
})OAvder proved successful, but a competitive material, 
DINA, proved to be more satisfactory than Fivonite 
(see Section 6.7, Albanite PoAvders). As a result, 
Fivonite Avas not used. The synthetic procedures de- 
scribed in the folloAving paragraphs, hoAvever, make 
it available if a demand should arise. 


0 

II 

c 



(IIOCII^)^^ CHCII^OH). 


C1I2 — cn, 

(II) 

0 

II 

c 

/ \ 

(o^Nocir,),^ c(ch20N0)2 


C14 — CII, 

(III) 

Fivonite is prepared from cyclopentanone hy means 
of tAV'o reactions. 

1. Purified cyclopentanone is mixed Avith formal- 
dehyde, as 57% formalin, in the ratio of 1 mole to 
4.2 moles. Sufficient freshly prepared calcium hydrox- 
ide is added to bring the pH of the reaction mixture 
to 9, and additional calcium hydroxide is added as 
necessary to keep the pH at this value. The reaction. 





EXPLOSIVE AND COMBUSTIBLE POLYMERS 


25 


wliicli is oxothorinii', is (‘oinplete in two hours. The 
base is neutralized witli hydrochloric acid and the 
product, Fivonc, 2,2,5,5-tctramcthylolcyclopeiitaiioiic 
(II), is isolated in DO to do^o yield by vacuum drying 
on the steam bath. This product is suitable for the 
nitration. 

2. Fivone, powdered to pass a 4 to 6 mesh screen, 
is added portionwise to six weights of 08^ nitric 
acid, stirred and cooled to IOC. The reaction is mildly 
exothermic. After 30 minutes the reaction is droAvned 
in about 4 Aveights of chipped ice Avith stirring. The 
product, FiA’onite, is stabilized by stirring under hot 
Avater, adding sodium carbonate to neutralize the acid, 
cooling, and decanting the Avater from the solidified 
Fivonite. The yield of once-stabilized product is 95^;. 
The procedure furnishes 4.3 pounds of once-stabilized 
Fivonite per pound of cyclopentanoned®^ 

The synthetic Avork described above Avas done Avith 
cyclopentanone i)repared from adipic acid. Tn order 
to make FiA’onite available in quantity, a synthesis 
from petroleum cracking fractions Avas dcA'eloped.^”® 
This synthesis involves the folloAving steps : 

1. Dehydrogenation of cyclopentanc to cyclopenta- 
diene. 

2. Hydrogenation of cyclopcntadiene to cyclopcn- 
tene. 

3. Hydration of cyclopentene to cyclopentanol. 

4. Dehydrogenation of cyclopentanol to cyclopenta- 
none. 

5. Condensation of cy('loj)entanonc and formalde- 
hyde to Fivone. 

The overall yield of Fivone is 57^^; based on cyclopen- 
tane, and plans are available for a pilot plant capable 
of producing 23,000 pounds of Fivone per day. 

In order to duplicate a German rocket poAvder, 
some 500 pounds of diethylene glycol dinitrate 
(DEGN) AA^ere prepared from diethylene glycol. No 
difficulty Avas experienced in nitrating the glycol in 
8.6-pound lots with a nitric acid ratio of 1.85 at a 
temperature of 50 F. The yield of Avashed neutralized 
DFGN Avas 75^/^. On the basis of this Avork there 
seems to be no reason Avhy the large-scale manufacture 
of DEGN should not be technically feasible.^®^ 

18 EXPLOSIVE AND COMBUSTIBLE 
POLYMERS^ 

In some of the early projects undertaken by Divi- 
sion 8, several problems arose which appeared to call 

®This section is constructed from a summary prepared by 
Ralph Connor. 


for binders of polymeric materials. Tyi)ical uses for 
such materials AA^ould be as binders in tracer and igniter 
coni])ositions and composite propellants and as sul)- 
stitutes for charcoal in time-ring fuzes. For such uses 
it AA’ould be desirable to have a series of binders con- 
taining varying amounts of oxygen in the binder 
molecules. In this Avay binders could be chosen Avhich 
AA'ould not seriously disturb the oxygen balance of 
the systems in Avhich they AA^ere used. Such materials 
wore not available, since the synthesis of polymers of 
such structures had not been studied. It, therefore, 
seemed AA'orth Avhile to sponsor scouting Avork in this 
field. A brief study Avas made at the IlniA’crsity of 
Illinois and a much more comprehensive one by the 
Rohm & Haas Conq)any. Research AA'as terminated 
Avhen a Avide variety of polymers had l)een prepared 
Avith a considerable variation in physical properties. 
At that time, it seemed advisable to make these mate- 
rials available for studies in mixtures before going 
further Avith the preparatiA^e research. Unfortunately, 
urgent projects have prevented the full evaluation of 
these materials as binders in explosive and propellant 
compositions. 

In addition to the general AA'ork mentioned above, 
a specific request Avas received for a study of the 
nitroindene polymer (NIP) developed in Great Brit- 
ain. Samples of this material Avere prepared at the 
University of Pennsylvania and submitted to Pica- 
linny Ai’senal for tests as a substitute for charcoal 
in time-ring fuzes. NIP proved to have interesting 
properties, but its development has not progressed to 
the stage of service applications. 

The polymeric materials for binders AA^cre prepared 
in three general Avays. 

1. The reaction betAA^een a molecule containing ni- 
tro groups and a polymer. See (a) and (c), beloAV. 

2. The nitration of polymeric materials. See (b) 
and (h), beloAV. 

3. The polymerization of materials cojitaining nitro 
groups. The materials to be polymeilzed Avere usually 
obtained l)y combining a molecule containing nitro 
groups Avith a second molecule Avhich is capable of 
undergoing polymerization. See (d), (c), (f), and 
(g), beloAV. 

By these procedures, polymers’’^’’'^^’^^®*”® of the fol- 
loAving types Avere prepared. 

a. Picryl and dinitrophenyl ethers obtained by the 
reaction betAveen picryl chloride or 2,4-dinitrochloro- 
benzene with phenol-formaldehyde resins. Products 
Avere prepared from phenol, cresol, and p-tert-butyl- 


iTuNFI liKNTIAt 


26 


PREPARATION OF HIGH EXPLOSIVES 


phenol. A typical structural unit in one of these 
polymers is shown in the formula below. 



b. Nitration products of the above ethers and of 
the poly benzyls. 

c. Azo resins obtained by coupling the diazonium 
salts from picramic acid or 2,4-dinitroaniline with 
various phenol-formaldehyde resins and with abietic 
acid. 



d. Polymerized nitrostyrenes. These products were 
obtained from w-nitrostyrene, m-nitro-w-nitrostyrene, 
l-nitro-2-furylethylene, and by the condensation of 
2,4,6-trinitrobenzaldehyde with nitromethane, and the 
condensation of trinitro-w« -xylene with formaldehyde. 

e. Polymerizable esters of trinitrophenyletlianol. 
When TNT is allowed to react with formaldehyde 
under appropriate conditions, a high yield of 2,4,6- 
trinitroplienylethanol is obtained. This alcohol was 
esterified with acrylic and other unsaturated acids. 
The resulting esters are readily polymerized. 

f. Nitroalkyl esters. Nitro alcohols may be obtained 
by the reaction of nitroparaffins with aldehydes. These 
nitro alcohols were converted to acrylate esters and to 
esters of other unsaturated acids. The esters polymer- 
ize readily. 


g. Products from the reactions of TNT or DNT 
with formaldehyde and amines. These reactions gave 
resinous products when TNT was used with primary 
amines or ammonia. When secondary amines were 
used with either TNT or DNT the products were not 
polymers but were crystalline /?-dialkylaminoethyl 
derivatives of tri nitrobenzene. 

h. Miscellaneous resins. These included resins ob- 
tained by the reaction of nitromethane and formal- 
dehyde with aniline and nitroaniline. Pesins obtained 
by the reaction of formaldehyde with fluorene or with 
phenol and aniline were nitrated. 

Stability and impact sensitivity tests were carried 
out on a considerable number of the products. It may 
be concluded from the information at hand that it is 
possible to prepare polymers which are readily com- 
bustible and which have melting points ranging from 
room temperature to well above 200 C. Products may 
be obtained which have satisfactory stability and 
sensitivity. 

A few attempts were made to use these resins in 
casting compositions containing a high percentage of 
solids and to use nitro esters as plasticizers in solvent- 
less double-base powders.^“ Neither of these experi- 
ments showed great promise, but the experiments were 
by no means exhaustive. 

19 MISCELLANEOUS HIGH EXPLOSIVES^ 

In this section are included a variety of candidate 
high explosives and intermediates which do not fall 
into any of the categories considered in the preceding 
sections. 

^ Analogs of Tetryl Containing 
Nitrate Ester Groups“^ “^ 

A number of aminoalcohols have become available 
or potentially available in recent years. Condensation 
of these aminoalcohols with dinitrochlorobenzene fol- 
lowed by nitration furnishes explosives analogous to 
tetryl, but containing, in addition to C-nitro and 
N-nitro groups, one or more nitrate ester groups. The 
general scheme of synthesis is illustrated with dini- 
trochlorobenzene and ethanolamine." 

‘'This section is constructed from information furnished by 
S. R. Aspinall. 

“Attempts to prepare some of the intermediates by the re- 
action between aniline or the nitranilines and glycerine mono- 
chlorohydrine or epichlorohydrine did not give satisfactory 
results. 


> -V I ' 1 1 1 K \ 'I' I \~i\ 


MISCELLANEOUS HIGH EXPLOSIVES 


27 


Cl 

/X 


NO, 


H 2 NCH 2 CH 0 OH 


NHCH 2 CH 2 OH 
NO, 


O 2 NNCH 2 CH 2 ONO 2 


NO, 


NO, 


O 2 N 


HNO 3 , 


NO, 


NO, 


Tlie eondonsation may be effected by adding the 
aminoaleoliol to an alcoholic solution of dinitrochloro- 
benzene and then adding one equivalent of aqueous 
alkali. Alternatively, the two organic reactants may 
be mixed, then fused, and the melt, after cooling, 
purified by crystallization. Purification of the dinitro- 
chlorobenzene by sweating improves both the yield 
and the quality of the condensation products. The 
structure of the aminoaleoliol affects the yield in the 
condensation and dictates the choice of experimental 
conditions to be used in the condensation. The nitra- 
tion, the second step in the synthesis, can be done with 
mixed acid, but dilute nitric acid alone giyes purer 
products in better yields. 

Two of the products obtained in the work — Heptryl 
( I ) and trinitrophenylisobntylolnitramine nitrate 
(IT) — showed promise but were found to offer no 
advantages over explosives already in use. 

(02N)3CeH2N(N02)C(CH20N02)3 

(I) 

( O 2 N) 3 CJT 2 N ( NO 2 ) C ( CH 3 ) 2 CTT 2 ONO, 

(II) 


The second was prepared from trinitrobenzyl bromide, 
either by treatment with silver nitrate or by hydroly- 
sis to the alcohol and subsequent esterification. 


NO 2 

0 .,N<(^^'^^^CH,Br -f AgN 03 - 

NO, 


0,N 


NO, 

"^CH, 0 N 02 

NO, 

(IV) 


In the same investigation the condensation of 
2 -nitrobenzaldehyde and 2,4-dinitrobenzaldehyde with 
nitromethane was shown to lead to stable nitroalcohols. 
The nitrates of these alcohols, however, lose nitric acid 
readily on warming in solution and furnish nitrosty- 
renes. 


0 ,n/ \c?TO + CH3NO2 — *• 
NO, 


Aliphatic-Aromatic Nitro Compounds 
and Nitrate Esters^*^ 

Two products (HI) and (IV), whose power in the 
ballistic mortar is equal to that of tetryl, have been 
prepared. The first of these was obtained by condens- 
ing 3,5-dinitrophenylnitromethane with formalde- 
hyde and nitrating the condensation product. 

0 ,N 

/ ^ CICNO^ + CH 2 O— > 

O 2 N 

O2N 

/ )> C(N03)(Cri30TT)3^ 

03 N 

N02 

/ ^ C{NO,){CB,ONO,), 

NO, 

(III) 


0,N<^ ^CHOHCH,NO, — ► 

NO, 

ONO 2 

0,n/ yCBCn,NO, 

^NO, 

0,Ny ^CH^CHNO^ 

NO, 

2,4,6-Trinitrobenzaldehyde does not condense with 
nitromethane. 

Also in the same investigation a study was made of 
the Ponzio reaction — the conversion of benzaldoxime 
to phenyldinitromethane by means of nitrogen diox- 
ide. Tt was shown that the reaction is best run by 
adding benzaldoxime to an ether solution of nitrogen 
dioxide. Attempts to extend the Ponzio reaction to 
0 - and p-nitrobenzaldoxime, to o,p-dinitrobenzaldoxi- 
me, and to 3-nitro-4-methoxybenzaldoxime were not 
successful. 


UlXriOILNTIAlil 


28 


PREPARATION OF HIGH EXPLOSIVES 


Nitrofurans^^® 

The study of the nitration of furans was under- 
taken because a number of furan derivatives are avail- 
able in large quantities, because 2,5-dinitrofuran has 
been reported to be comparable with TNT as a high 
explosive, and because no satisfactory procedure is 
known for the preparation of dinitrofuran or any 
other polynitrofuran. The study showed that, while it 
was usually possible to introduce a nitro group in the 
b-position of a furan derivative appropriately sub- 
stituted in the 2-position, it was not possible either 
to nitrate in the 3- and 4-position, or to introduce 
more than one nitro group. Since no furan deriva- 
tives sufficiently highly nitrated to be of interest as 
explosives were obtained, a list of those nitrofurans 
which were prepared and those which could not be 
prepared is not given here. This information is avail- 
able in the original report. 

The reasons which prompted the study of the nitra- 
tion of furans are still valid. As a result of the study 
which has been made, however, it is clear that the 
status of this proldem is the same as that of the 
nitroparaffins discussed in Section 1.6; a considerable 
increase in our knowledge of the chemistry of furans 
will be necessary before we can hope to prepare nitro- 
furans which will be of interest as explosives. 

Trinitro-m-xylene^^^ 

Trinitro-we/a-xylene has received a certain amount 
of attention as an explosive and for this reason it 
appeared desirable to investigate the possibility of 
increasing the supply of /y/c/a-xylenc should a large 
demand for the material suddenly arise. 

Commercial xylene is a mixture of ortho, para, and 
ineta isomers, only the last of which can be converted 
readily to a stable trinitro derivative. It has been 
found that heating commercial liquid xylene with 
anhydrous aluminum chloride does not result in an 
increase in the percentage of the meta isomer at the 
expense of the other two. This is consistent with the 
fact, previously reported and confirmed during this 
work, that each of the pure isomei’s when heated with 
aluminum chloride is converted to an equilibrium 
mixture of isomers which docs not differ significantly 
in composition from commercial xylene. 

Mixtures of commercial xylene and naphthalene were 
heated with aluminum chloride in the hope that the 
ortho and para isomers would methylate the naphtha- 
lene and leave a mixture of niela-xy]ene and toluene. 
However, very little toluene was formed and the meta- 


xylene content of the commercial xylene was un- 
changed. 

Aminoguanidine^^® 

The preparation of aminoguanidine was studied in 
order to make available this raw material for the 
synthesis of tetracene. The reduction of nitroguani- 
dine with zinc and hydrochloric or acetic acids gave 
aminoguanidine of poor quality in poor yield; the 
product contained zinc, which was difficult to remove. 
The reaction between methyl isothiourea sulfate and 
hydrazine furnished aminoguanidine in quantitative 
yield. The reagents used in this reaction are so expen- 
sive, however, that the process is not practical. 


NH^ 


NH2 

1 

\ 

\ 


/ 

C 


C 

\ 

H^SO, 

\ 

SCH, 


NH^ 

i 

NH 2 HN 2 

11 

NH 

> 

2 * 

NH 


Electrolytic reduction of nitroguanidine furnished 
aminoguanidine in 75^ yield. The reduction is car- 
ried out in a 5^ solution of sulfuric acid, using amal- 
gamated lead cathodes, with a current density of 1 
amp per square decimeter; the current efficiency is 
38^. The bulk of the aminoguanidine is isolated as 
the acid sulfate, the remainder as the bicarbonate. 
Electrolytic reduction should be suitable for the com- 
mercial pi'eparation of aminoguanidine at an esti- 
mated cost of 50 cents to $1.00 per pound. 

^ ^ ^ Other Candidate High Explosives 

Preparatory procedures have been worked out for 
the 5tVtrinitrophenyl ether of ethylene glycol, for 
^-(2,4,6-trinitrophenoxy) ethyl nitrate, for hexanitro- 
di])henylethylenedinitramine (ditetryl), and for tri- 
nitrophenylguanidine. Attempts to synthesize nitrated 
hydroxyethylguanidines were not successful. No prac- 
tical synthesis of hexanitroazobenzene could be de- 
veloped. Some nitrated phenylbenzotriazoles were pre- 
pared, but they were not attractive as high explosives. 

1 10 PLASTIC HIGH EXPLOSIVES^ 

P>y 1941 the British had developed and put into 
use the plastic high explosive PE-1. This material, 

'"This section is taken from reports^i^ by E. H. Eyster. 




PLASTIC HIGH EXPLOSIVES 


29 


which has the consistency of a good modeling clay, 
contains 88.3^ JIDX plasticized and desensitized by 
11.7% of a special PE oil. Its plasticity permits it to 
be molded by hand and its stickiness ensures inti- 
mate contact with the target, so that full advantage 
may be taken of its high brisance. It is particularly 
suited for the attack of I’ails, girders, and other steel 
targets of irregular outline, since it may be shaped 
in the field. At the same time, the plasticizing oil 
greatly desensitizes the material, so that it is relatively 
safe to handle and carry even under fire. Such a mate- 
rial is clearly an ideal agent for light demolition and 
sabotage. Indeed, the British production of PE-I and 
its successor, PE-3 were almost completely allocated 
to special service forces and to underground forces 
within enemy-occupied countries. For such use the 
finest plastic properties were demanded, but great 
tonnages were not required. These circumstances have 
naturally determined the British acceptance stand- 
ards for plastic explosives; since all our original in- 
formation concerning plastic explosives was derived 
from British sources, our ideas of what constituted an 
acceptable plastic explosive, were also thus determined. 

In October 1941, attempts to prepare British 
PE-1 were begun at the Explosives Pesearch Labora- 
tory. The PE-1 oil is prepared by heating 10% of 
crepe rubber in a 3/1 vaseline-paraffin oil base at 
150 C for about 15 to 16 hours with vigorous stirring. 
The plastic is prepared from this oil and KDX of 
which 50 to 70% should be through 30 and retained 
on 300 USS Sieve, and 30 to 50% should be through 
a 300 USS Sieve. Twelve parts of molten PE oil 
are added to 88 parts of PDX as a 5/1 (water-EDX) 
slurry in hot water. After about 5 to 10 minutes’ stir- 
ring, the PiDX is well coated with oil; excess water is 
then liltered off, the wet product is roll-milled and 
finally dried. Experimental work with PE-1 con- 
tinued until May 1943 and consisted in the main of 
attempts to prepare suitable PE-1 oils, studies of 
proper milling and drying conditions; and, finally, 
the preparation of a motion picture showing the 
preparation of PE-1 and typical uses of the plastic 
explosive, intended to stimulate interest in plastic 
explosives among the Services. 

By this time the British were at work on a new 
plastic which would avoid the use of rubber, both be- 
cause it was becoming short in supply and also because 
PE-1 deteriorated on aging, particularly in the pres- 
ence of air and light. The period of study of PE-1 at 
the Explosives Pesearch liaboratory served therefore 
mainly as an introduction to the art of preparing good 


plastics. During this period it was established that the 
particular difficulty with PE-1 (and, it appears, with 
most similar plastics) is to get the material through 
the drying stage without notable deterioration in 
plastic properties; only if the milling technique is 
correct can this be achieved. Xo PE-1 sample was 
made in which the behavior during drying could be 
considered ideal; but changes in the springing of the 
rolls (the rolls were originally held rigidly at a pre- 
determined separation) made it possible to obtain 
fair products, whereas the early batches dried to hope- 
lessly crumbly materials. It was found, however, that 
excellent PE-1 samples could be made by a dry proc- 
ess, the molten oil being mixed with dry PDX and 
the milling being carried out dry. This dry process 
was later used for rapid tests of substitute PE oils, 
on the assumption that unless an oil could produce 
a good plastic under these circumstances it could not 
produce a good plastic by the wet process. 

In May 1943 work began on development of sub- 
stitutes for the PE-1 oil. First, substitutes for the 
rubber only were studied, no attempt being made to 
modify the 3/1 vaseline-paraffin oil base; but later 
other oils were studied, either alone or with the addi- 
tion of vaseline, wax, or materials like lecithin, lan- 
oline, Alox, believed to act as surface agents. By the 
end of 1943 the art of roll-milling was well devel- 
oped, and a 66/34 vaseline- Yoltolized rapeseed oil 
mixture had been produced as a substitute PE oil. 
At the same time, however, the British PE-3 oil, 
110/55/10 vaseline-paraffin oil-lecithin, had been de- 
veloped and a sample of this oil had been received. 
Plastics made with the two oils were carefully com- 
pared, and it was decided that the Yoltolized rape- 
seed oil product was not clearly superior to the British 
PE-3. 'The latter material was then adopted for 
manufacture in this country as PDX Composition C. 

It was then soon found that both British PE-1 and 
(Composition C (British PE-3), and also the 66/34 
vaseline-YPO plastics l)ecame very hard and difficult 
to mold at low temperatures, owing to their vaseline 
content. This finding led to the request that a plastic 
explosive be developed which could be molded at low 
temperatures. PDX Polar PE, based on a viscous 
high-viscosity lubricating oil plus lecithin, was devel- 
oped to meet this request. This plastic has the com- 
position 88/13 PDX-oil; the oil is a 95/5 mixture 
of Gulf 300 Process Oil and lecithin. At the same time 
the du Pont Company developed an PDX plastic 
plasticized with a mixture of nitrotoluenes thickened 
with nitrocellulose. This material remained workable 


fONFinEKTTA^ 


30 


PREPARATION OF HIGH EXPLOSIVES 


at low temperatures for a considerable period due to 
supercooling of the plasticizer, and excelled Composi- 
tion C in low-temperature plasticity. It is not of high 
quality as a plastic and tended to deteriorate further 
in plastic properties during hot storage. It could, how- 
ever, he turned out in far greater tonnages than Com- 
position C or the IlDX Polar PE and was somewhat 
more powerful. It was adopted as Composition C-2 
and, together with a later variant. Composition C-3, 
has been the plastic explosive used hy the U. S. Army 
Engineer Corps. 

In ^lay 1943 a request was issued for plastic ex- 
plosives based on some other explosive than PDX, 
but which could be reliably fired by an Engineer Spe- 
(*ial Detonator. This last requirement eliminated ex- 
plosives based on TXT, ammonium picrate, or tetryl. 
In August a PETX plastic, PEP-2 (85/15 PETN- 
(iulf Crown Oil E) had been developed. It was 
modified, after a pilot-batch had been made at the 
Eastern Laboratory of the du Pont Company, to an 
86/14 PETX-Oil composition and was then called 
PEP-3. During the preparation of a second pilot- 
batch it was found that this material collected static 
electricity and, during the extrusion process employed 
in the packaging operation, produced large sparks. 
Attempts to prevent this by increasing the conduc- 
tivity of the oil were not successful. In the meantime, 
PDX production had so increased that need for such 
a material had passed. PEP-3 did, unexpectedly, 
prove superior to PDX plastics in one respect: it was 
much more difficult to set on fire. 

In Xovemher 1943 a request was made for an 
explosive whose plastic properties might be rather 
poor, but whose sensitivity should be distinctly lower 
than that of Composition C-2. For this purpose two 
insensitive semiplastics were suggested, RIPE (85/15 
RDX-Gulf Crown Oil E), and PIPE (81/19 PETX- 
Culf Crown Oil E). It was intended that these mate- 
rials would be used to load special shells and rocket 
heads for ‘^plaster shot’’ attacks against reinforced 
concrete. About a year later, lots of each plastic were 
made at Picatinny Arsenal ; only the RIPE proved 
satisfactory, hut it had rather a low density and, al- 
though tested, has not been used in service. 

1 11 EXPLOSIVE COMPOSITIONS^ 

A highly characteristic development of World War 
11 was the use of such sensitive and powerful high 
explosives as RDX, desensitized by the addition of 

^This section is based on reports prepared by E. H. Eyster. 


either a less sensitive, less powerful explosive, such 
as TXT, or a wax, or both. In this section is de- 
scribed the M'ork done by Division 8 on the develop- 
ment of these explosive comi)ositions. For complete- 
ness of coverage reference should also be made to the 
PT Interim Reports of Division 8. 

1 Composition 

This RDX composition, developed hy the British 
in order to reduce the sensitivity of RDX sufficiently 
to permit its use as the main filling in projectiles, was 
composed of RDX and beeswax in the ratio 91/9. 
Beeswax is an excellent desensitizer, but it was not 
available in amounts adequate for the large produc- 
tion of densitized RDX envisaged in the United 
States. A search was therefore made for substitutes 
for beeswax. From the wide variety of waxes examined 
the conclusion was drawn that practically any petro- 
leum-base wax becomes a possible substitute for bees- 
wax if some polar additive, such as, for example, 
Alox 600, is added to the wax in amounts of from 
1 to 10%. Such a modified wax will wet RDX from 
water in the same way as does beeswax, and almost 
any such wax seems to have about the same desensitiz- 
ing action as beeswax. The most satisfactory substi- 
tutes for beeswax must therefore be chosen not on the 
basis of any special effectiveness as desensitizers but, 
rather, on the basis of availability, physical proper- 
ties (such as consistency, melting point), and ability 
to withstand hot storage without exudation of oil or 
low-melting wax. A series of such substitute waxes 
was recommended for Composition A early in 1942. 
One of them, which has been called Bruceton Wax 
No. 10, was adopted and has been used both in 
Composition A and in Composition B (see below). 
Bruceton Wax No. 10 has the composition 90/10 
Aristowax 160-165 (Union Oil Company of Cali- 
fornia) — Alox 600 (Alox Corporation, Niagara Falls, 
N. Y.). Subsequent studies showed that even more 
desirable substitute waxes are available for use in 
Composition A; a 99/1 Stanolind Wax 170-175, Alox 
600 mixture seems particularly good from the stand- 
point of exudation. 

Composition 

The British Composition B was composed of RDX- 
TNT-beeswax in the proportion 60/40/1. Bruceton 
Wax No. 10 was found to be a satisfactory substitute 
for the beeswax in the composition. In Composition 
B, desensitization of the RDX is accomplished mainly 
by the TNT, although the wax makes a real, albeit 




EXPLOSIVE COMPOSITIONS 


31 


Table 1. Properties of plastic explosives. 



Composition C 
(British PE-2) 

(1) 

ERL 
66/34 
vaseline- 
VRO PE 
(2) 

ERL 
RDX 
Polar PE 
(3) 

Du Pont 
composi- 
tion C-2 
(4) 

ERL 

PEP-1 

(5) 

ERL 

PEP-2 

(6) 

Du Pont 
PETN 
gelatine 
SWV-9 
(7) 

ERL 

RIPE 

(8) 

ERL 

PIPE 

(9) 

1. Physical properties 










a. Density (25 C; 










g/cc) 

1.00 

1.01 

1.00 

1.57 

1.48 

1.47 

1.50 

1.36 

1.31 

b. Extensibility 










(25 C; mm) 

11 

22 

~50 

9 

3 

13 




c. Compression 










plastometer 










con.stants: 

a h 

a b 

n h 

a b 

a b 

a b 



.... 

25 C 

11 7 

15 10 

11.4 65 

3.3 27 

9.5 3.9 

25 45 




OC 

'^2 at 15 -^3 at 15 

Hardens 

7.0 14 

3.3 7.6 


11 29 




— 20C 


about 

4.1 5.5 

3.3 4.6 

3.3 11.0 





— 35C 


like (1) 

1.5 3.7 

2.5 4.2 


2.6 3.9 




d. Sagging test (25 










C : mm) 

3 

8 







.... 

e. Stickiness [25 C; 










Wio(g)] 

230 

230 

51 

23 

168 





f. Remarks on 

Excellent plastic 

Very ex- 

Softer than 

Fair plastic 

Good 

Rather like (3), 

Some- 

Semi- 

Semiplastic 

plasticity 

at 25 C 

tensible ; 

(2) at 25; 

when fresh 

plastic— 

but usually less 

what like 

plastic 




softer than 

in general 


generally 

soft 

(4), but 



2. Explasive proper- 


(1) in gen- 



shorter 


more 



ties 


eral 



than (1) 


gelatinous 



a. Bullet test (% 










inert) 










Cal. .30 ball, l" 


80% 

100% 

100% 

100% 

90% 

50% 



pn 

100% (4 trials) 

(5 trials) 

(10 trials) 

(10 trials) 

(6 trials) 

(20 trials) 

(10 trials) 



Cal. .50 ball, 






44% 


100% 


2x3" pn 



100% 

40% 

.... 

(9 trials) 


(20 trials) 

66% (19 trials)* 

Cal. .30 ball. 



(1 trial) 

(10 trials) 


100% 




Yi" backed 




100% 


(2 trials) 




Vi” steel 




(2 trials) 






b. Flame sensitiv- 






Will not break 




ity (II) 



138 

178 


in test 

50 

162 

.... 

c. Cap sensitivity: 










No. 6 fulm. chi. 



3 NE 

3 NE 

5E 

10 NE 

5 NE 



No. 8 Tetryl 

10 E (10 trials) 

10 E 

(3 trials) 

(3 trials) 

(5 trials) 

(10 trials) 

(5 trials) 



d. Velocity of deto- 


(10 trials) 

25 E 

23 E 


10 E 

5E 



nation (m/.sec) 

8100 

8100 

(25 trials) 

(25 trials) 


(10 trials) 

(5 trials) 



(density) 

(1.590) 

(1.590) 

8110 

7800 


7540 


7320 

6930 

e. Ballistic mortar 



(1.581) 

(1.579) 


(1.42) 


(1.35) 

(1.31) 

(TV) 

125 

125 

125 

142 






f. Brisance-plate 





108 

115 


118 

^106 

denting test. 










(Cast TNT = 










100) 










Method A; 

112 

(112) 

(112) 

118 

95 

100 

.... 



(density) 

(1.581) 



(1.572) 

(1.488) 

(1.487) 



• 

Method B; 







~110 

85 

76 

(density) 




111 


.... 

(1.50) 

(1.37) 

(1.33) 





(1.52) 






3. Stability 










a. 135 Thermal sta- 










bility 


.... 

Not acid 

Not acid 

Acid 95' 

Acid 160 


.... 


b. Vacuum stabil- 



300' 

300' 






ity in 90' (gas 










evolved-cc) in 



^■^Hi20C 

^■^|l20Ct 

‘'•"‘^llOOC 

>12, 48 hr 120 C 

— 

''•"H 12 OC 

>12, 48hr 120 C 

48 hr 



7.7 j 


3.22J 

~0.3.48 hr 100 C 


0 . 54 / 

0.5, 48hr 100 C 

c. Exudation, 










closed (% total 










wt lost at 50 C 










in 1 week) 

0.8% 

0.7% 

0.3% 

3.0% 


1.2% 

4.4% 

25% 

6.1% 

d. Remarks on stor- 

Very good at ele- 

Very good 

Same as (1) 

Extensibil- 

Hardens in 

Very good. Sam- 

Same as 

(60 C) 

(60 C) 

age stability of 

vated and ordi- 

retention 

Samples 

ity quickly 

storage. 

ples stored 2 yr 

(4), or 



plastic proper- 

nary temperatures 

at ordinary 

have been 

deteri- 

esp. at 

are in perfect 

perhaps 

.... 


ties 

if lecithin is good. 

and ele- 

stored 2)^ 

orates. 

elevated 

state 

poorer 





vated temp. 

yr at ord 

Hardens in 

temp 







Stored 3 

temp and 

elevated 








years in per- 

are still 

temp 








fect state 

perfect 

storage 







♦Only with PIPE have high-order failures in the bullet test been obtained. 

tThis result is not very meaningful because of the volatility of the plasticizer in Composition C-2. 


(cOXFiriKNTTAld 


32 


PREPARATION OF HIGH EXPLOSIVES 


relatively small, contribution to the desensitization. 

Composition B is used for the pour tilling of pro- 
jectiles. Consequently a great deal of time and effort 
have gone into the study of the factors determining 
the consistency and the flow properties of the mate- 
rial. The effects of temperature, concentration of 
BDX, grist of BDX, stirring, and surface-active 
agents have been studied in detail and are described 
in the reports already cited. 

1.11.3 Miscellaneous Explosive 

Compositions 

As part of the development of Haleite (see Sec- 
tion 1.3) mixtures of Haleite and TNT, known as 
Ednatols, have been prepared and studied for com- 
parison with Pentolite and Composition B. It is pos- 
sible to prepare Ednatols which are pourable and 
which are less sensitive than Composition B; these 
pourable Ednatols, however, are inferior to Composi- 
tion B in stability, density, and performance. A 
surface-active agent, the acetone extract of soybean 
lecithin, has been found to improve the fluidity of 

Ednatols.^28.129 

Analogs of Cyclotol, Pentolite, and Ednatol have 
been prepared from RDX, PETN, and Haleite using 
Eivonite in place of TNT. Since Fivonite is more 
powerful than TNT, it was expected that these com- 
positions would be more powerful than the corre- 
sponding ones made with TNT. This was found to 
be so, but the improvement in performance was ac- 
companied by so marked an increase in sensitivity that 
the Fivonite compositions were not felt to be of any 
practical value.^®'^ 

Brief studies, to be found in the PT Interim Re- 
ports, were made on the explosive properties and 
pouring properties of such compositions as PTX-1, 
PTX-2, 70/30 Cyclotol, and 52/18 Picrotol. 

112 ALUMINIZED EXPLOSIVES^ 

The introduction of aluminized explosives for un- 
derwater and air blast use was, like the introduction 
of the explosive compositions treated in the preceding 
section, characteristic of World War II. In this sec- 
tion is presented the work done by Division 8 on the 
development of aluminized explosives. 

1-12-1 Torpex-2"^®'^^^ 

This explosive, having the composition 12/40/18 
RDX-TNT-Al, was developed by the British for use 

^This section is based on reports prepared by E. H. Eyster 
and Frank H. Westheimer. 


as a cast filling for underwater weapons. Torpex-2 is 
made by adding the appropriate amounts of TNT and 
aluminum to Composition B; accordingly, Torpex-2 
made in this country contains about 0.6^ of Brnce- 
ton Wax No. 10. Studies have been made of the flow 
properties of Torpex-2 and of the effects of wax, of 
alnminnm grist and purity on the sensitivity of the 
explosive. It was not possible to detect any sensitiz- 
ing effect of alloyed impurities in the aluminum. 
However, a close dependence of bullet sensitivity on 
aluminum grist was observed. The coarser the alu- 
minimum the less sensitive the Torpex-2. 

1122 hex 

In England a mixture known as D-I or PNL was 
developed for the purpose of desensitizing Torpex-2 
and certain other high explosives. The mixture has 
the composition 81/11/2 paraffin-nitrocellulose (12% 
nitrogen; Yz sec viscosity) -lecithin, the nitrocellu- 
lose and lecithin serving as emulsifying agents for 
the wax. Torpex-2, containing 5 parts of D-I, is 
known as Torpex D-I. In this country the effective- 
ness of D-I as a desensitizer was recognized, but there 
was reluctance to use it for two reasons : the danger 
of exudation of wax on hot storage, and the danger 
of decomposition of the nitrocellulose which, by con- 
trast with the high-explosive ingredients present, is 
a relatively unstable material. 

Extensive studies were made of higher melting 
petroleum-base waxes as substitutes for the low-melt- 
ing paraffin used in D-I. As a result of these studies 
several available waxes and blends of waxes have been 
recommended which give good desensitization with 
very little exudation. HBX, which differs from Tor- 
pex D-I only in the substitution of a higher melting 
petroleum-base wax for the 135 F paraffin, has been 
adopted by the IT. S. Navy.^^s.iao.iai 

Another investigation showed that Yinylseal MA- 
28-11 was an excellent substitute for nitrocellulose 
and lecithin for emulsifying the wax in HBX.^’"’- 
ddiis development, together with that detailed in the 
preceding paragraph, makes possible the preparation 
of a desensitized Torpex that does not exude on hot 
storage and that does not contain such an unstable 
ingredient as nitrocellulose. 

Finally, extensive studies were made of the sensi- 
tivity of HBX, both in comparison with other ex- 
plosives and as a function of such variables as alu- 
minum grist and agglomeration. As with Torpex-2 
coarser aluminum gives a less sensitive product. Light 
agglomeration of the aluminum acts the same way.^^® 




ALUMINIZED EXPLOSIVES 


33 


Baronal 

Tliis explosive, which has the composition 50/35/15 
l>a(X 03 ) 2 -TNT-Al, was developed as a castable fill- 
ing for underwater munitions. The mixture has a 
cast density of 2.27 g per cc and is almost equal to 
Torpex-2 in nnderwater performance on a volume 
basis. It was hoped that the mixture would be much 
less sensitive than Torpex-2. Surprisingly enough, 
Baronal was found to be in the same general sensi- 
tivity class as Torpex-2, and Torpex-2 rather than 
Baronal was adopted as an nnderwater charge.^^''^ 

1.12.4 Miscellaneous Aluminized Explosives 

Aluminized Composition A^s have been prepared 
and briefly studied. They are made by adding atom- 
ized alnminnm to Composition A-3 just after the wax 
has been added to the BDX-water slurry. The composi- 
tion 73/9/18 BDX-wax-Al was considered for press 
loading into shells; and the composition 70/5/25 
BDX-wax-Al was pellet-loaded in a Tritonal matrix 
so that the overall charge had the same composition 
as Torpex-2. 

Some study has been made of the pouring proper- 
ties of the Tritonals, particularly of the segregation 
of aluminum in 80/20 Tritonal castings. 40/60 Tri- 
tonal can he detonated. Both 80/20 and 40/60 Tri- 
tonal can be appreciably desensitized by the addition 
of 5 parts of desensitizer 4)-2. The use of coarse alu- 
minum desensitizes 80/20 Tritonal. 

Dentex, 48/34/18 BDX-DXT-Al, was developed 
as a substitute for Torpex-2. Its underwater perform- 
ance is somewhat inferior to that of Torpex-2, hut 
its sensitivity is significantly lower. However, this 
advantage was offset by the development of Torpex 
D-I and HBX, which are more powerful and less 
sensitive than Dentex. 

Pentonal, 47/33/20 PETX-TNT-Al, is very sen- 
sitive to bullets. Torpex-2 analogs in which the BDX 
was replaced by Haleite and by Fivonite showed good 
performance. 

1.12.5 Q^g Evolution from Aluminized 

Explosives 

The extensive use of aluminized explosives has re- 
vealed two difficulties peculiar to this type of filling; 
both result from the evolution of gas from the explo- 
sive. The first is known as spewing. Gas liberated 
from the molten explosive causes the rapid ejection 
of some of the material from the container during 
filling operations. The second is known as gassing. 


It is the evolution of gas from the solid explosive in 
a filled munition. Gassing can result in deformation 
of the booster cavities and battery cases in mines, 
and, when the gas is inflammable, it creates a fire 
hazard. Spewing has been observed principally with 
Minol ; gassing is more serious with Torpex. Since 
Minol is not loaded in this country, spewing is not a 
serious problem here. The gassing of Torpex-filled 
stores is serious, however, and the succeeding para- 
graphs describe the successful methods developed to 
prevent gassing of Torpex and, incidentally, DBX 
and Tritonal. 

The gas evolution from Torpex results from the 
presence of water in the explosive. The water is in- 
troduced with the Composition B which is made from 
water- wet BDX. It has proved impractical to dry 
Composition B, or to coat the aluminum in Torpex 
so that it will not react with water. Consequently, it 
has been found necessary to dry the Torpex itself. 
Attempts to do this by increasing the time of batch- 
ing the Torpex failed. However, the addition of 0.5% 
of anhydrous calcium chloride to Torpex was suc- 
cessful. Torpex containing 0.5% of anhydrous cal- 
cium chloride generates little gas at elevated tem- 
peratures and essentially no gas at room temperature. 
Addition of calcium chloride introduces no new prob- 
lems. Torpex containing 0.5% calcium chloride is 
indistingnishahle from ordinary Torpex in sensitivity 
and stahility. The calcium chloride makes the mixture 
very slightly hygroscopic, but the effect is small and 
the mixture is less than one per cent as hygroscopic 
as Minol. Torpex to which 0.5% of calcium chloride 
has been added has been adopted by the U. S. Navy.^^® 

Tritonal will evolve gas when the explosive is wet. 
However, the ingredients from which Tritonal is 
made, TNT and aluminum, can easily be obtained 
free from moisture, so it should be possible to prepare 
dry Tritonal which will not generate gas. However, 
0.5% of anhydrous calcium chloride will effectively 
stop the gassing of moist Tritonal.^''*® 

The gas evolution from Minol and DBX, both of 
which contain ammonium nitrate, can also be pre- 
^'ented. At low temperatures Minol, even when it 
contains several tenths of a per cent of water, does 
not generate much gas. The addition of a few per cent 
of anhydrous magnesium nitrate and 0.1% of stearo- 
xyacetic acid reduces considerably the gas evolution 
from solid and from molten Minol at elevated tem- 
peratures. Similarly, the addition of 0.5% of anhy- 
drous magnesium nitrate and 0.1% of stearoxyacetic 
acid stops the gas evolution from DBX.^^^’^"*^ 


I OXFlDFVfTAg 


Chapter 2 


THE PROPERTIES OF HIGH EXPLOSIVES 


^HE WOKK on the preparation of high explosives 
described in the preceding chapter required as a 
parallel activity an evaluation of the various candi- 
date explosives prepared. For the most part these 
candidate explosives coidd be screened on the basis 
of tests of a relatively small number of properties — 
stability, power, sensitiveness to impact — tests which 
can be made with relatively small amounts of ma- 
terial. For the explosives which met these screening 
tests satisfactorily, further and more extensive test- 
ing was necessary. With both the preliminary and the 
subsequent tests, considerable work was necessary on 
the development of the testing methods themselves. 
Consequently the work described in this chapter deals 
both with the study of testing methods and with the 
results of the tests. 

In addition to the testing program mentioned in 
the preceding paragraph and described in Sections 
2.1 through 2.5, various other activities dealing with 
the properties of explosives were undertaken. Thus, 
in order to make the information available to inves- 
tigators working on the synthesis of organic explo- 
sives and on their applications, a compilation of data 
on the properties of organic explosives was prepared. 
The data include physical properties, methods of 
preparation, explosive properties, and stability. The 
emphasis in the compilation was on high explosives 
rather than primers or detonators, and on pure com- 
pounds rather than mixtures. The data were taken 
in part from the open literature beginning January 
1, 1907, and in part from the following classified 
sources. 

1. OSFD reports issued to January 1, 1944.‘‘‘ 

2. British reports available in the NDBC files to 
January 1, 1944. 

3. Canadian reports available in the NDRC files 
to January 1, 1944. 

4. Records at the Picatinny Arsenal. 

5. Records at the Naval Powder Factory, Indian 
Head, Maryland. 

^A. H. Blatt, OSRD-2014, February 1944. An earlier com- 
pilation by A. H. Blatt and Frank C. Whitmore, OSRD-1085, 
December 1942, was issued in order to make available as 
quickly as possible a part of the data. All the information in 
OSRD-IO 80 is given in the final report, O8RD-2014. 


6. Information made available by F. I. du Pont 
de Nemours & Company. 

7. Information made available by the Hercules 
Powder Company. 

A number of reports on the properties of individual 
explosives or on a detailed comparison of two or three 
explosives were issued by Division 8. From the na- 
ture of the subject material it is not possible to give 
useful condensations of the content of these reports; 
we shall, therefore, simply name the subjects and 
refer to the reports: NENO and MNO;^ Cyclotol, 
Ednatol, and Pentolite;- Fivonite and Fivonite Com- 
positions and Minol and Torpex^. 

The effect of moderate heating on explosives is 
measured in a variety of tests designed to determine 
the stability of high explosives (see Section 2.1). 
A more immediately practical study was made of the 
“cooking-off” phenomenon, the explosion of shells 
which have been left in overheated guns. It was 
found that the explosions result from the detonation 
of mercuric fulminate which takes place when that 
material is heated to 135 C or higher. During the 
study the explosion temperatures of nearly twenty 
of the more commonly used high explosives and ex- 
plosive compositions were determined.^ 

44ie effect of applying high pressures to explosives 
was examined,*^ and it was found that the common 
high explosives are not detonated by the isothermal 
application of hydrostatic pressures up to 50,000 
kg per sq cm combined with sheating stresses up to 
the maximum which the explosives would support. 
Pressures up to 100,000 kg per sq cm could be ap- 
plied slowly to TNT, ammonium picrate, and nitro- 
guanidine without causing explosions. 

An entirely different aspect of the study of the 
properties of high explosives was brought to light by 
the request for inert simulants of various explosives. 
The simulants, which must match the physical prop- 
erties of a given explosive, are used as “stand-ins” for 
the explosive in making certain tests. Thus a simulant 
might be used as tlie filling for studying the effect 
of changes in design and material on the armor- 
piercing ability of an armor-piercing jDrojectile. A 
mixture of 5^ of Celite 535 ( Johns-Manville Com- 
pany) and 95% of Aroclor 2505 (Monsanto Chemical 


IroMiiiKS n aeI 


34 


STABILITY 


35 


Company) ])roved to bo a close simulant tor IIBX, 
as the (lata in Table 1 show/ 


Table 1. Physical {)roperties of HBX and HBX 
simulant. 


Property 

HBX 

Simulant 

Laboratory density g per cc 

1.66 

1.74 

CompressiA^e strength psi at 



density d 

3,280 ±300/1.72 

3,420 ± 200 

Modulus of elasticity, dynes 



per sq cm at density d 

8.95 X 10‘VL69 

6.6 X 1010 

Specific heat cal per g per C 

0.24 at 15C 

0.25 at 26 C 

Impact strength (IZOD) ft-lb 

at 


density d 

0.070 

0.047/1.68 


21 STABILITY‘S 

All military high explosives possess at least rea- 
sonably good stability, otherwise they are not adopted 
for service use. In this respect the stability problem 
differs from the sensitivity problem to be discussed 
in the next section. There are service uses for sensi- 
tive explosives ; there is no service use for an unstable 
explosive. Military high explosives must be and are 
stable to lieat over a long period of time. It is desir- 
able that they be stable to moisture as well, but this 
is by no means essential since the containers (shells, 
mines, rocket heads, etc.) for these exjdosives are 
tightly closed. The methods for testing the stability 
of high explosives which were used at the Explosives 
llesearch Laboratory are outlined below, together Avith 
data on the stability of some of the high explosives 
tested there. Oidy cursory testing Avas done on most 
of the standard explosives of recognized stability such 
as ammonium picrate, picric acid, amatol and the 
like. 

Tests 

Tests used at the Explosives Besearch Laboratory 
were in ])art Avell-knoAvn tests ('arried out as described 
in the open literature. In part, hoAvever, modified 
apparatus and modified })rocedures Avere used, and 
reference should be made to the original reports for 
details.®’^’ 

PUKITY 

Since all pure samples of a ])ariicular high explo- 
siA’e behave alike, once the general stability of an 

‘’This section is constructed from information supplied by 
Frank H. Westheimer. 


exjdosive has been established it is only nec^essary to 
determine that subsequent samples are pure. The cus- 
tomary criteria of jnirity are melting point, and 
either acidity or basicity or /;H. Many explosives, for 
example tetryl, are unfavorably affected by small 
amounts of acids or bases as impurities, and service 
samples of these materials must be essentially neu- 
tral. Observations of the color and odor of samples of 
explosives Avill often give preliminary indications of 
purity or, rather, indications of gross imj^urity. 

1 XTEJrXATIONAL TeST 

The sample is heated in an open vessel for forty- 
eight hours at 75 0. Changes in appearance or Aveight 
are noted. The test serves to eliminate ex(‘essively 
volatile explosives. 

T n EEMA L Stability 

The sample is heated in a loosely stoppered glass 
tube Avith a piece of methyl violet paper aboA^e the 
surface of the explosive. The test is run at 100 C 
and at 135 C for ‘five hours. The time required for 
the color of the methyl violet paper to change to a 
l)right salmon pink, and the time required for the 
sample to explode are noted if either of these events 
occurs Avi thill the fiAT-hour period. This test serves 
to eliminate explosives of very inferior stability. 

Hyuboscopkaty 

The sample is exposed to atmos})heres of various 
high relative humidities in a Aaciium desiccator at 
room temperature for five days, or until equilibrium 
is established if this requires more than five days. 
The gain or loss in Aveight of the sample is noted. 
Some military explosives (in particular those such as 
amatol or Minol Avliich contain animoinum nitrate) 
are quite hygroscopic. This does not necessarily ex- 
clude them from service use. HoAvever, hygroscopicity 
is ahvays a disadvantage and does eliminate an explo- 
sive for some uses. Other things lieing equal, a non- 
hygros(‘o])ic explosive is preferable to one Avhich is 
hygros('oj)ic. 

\/v('ruM Stability 

This test measures the amount of gas liberated from 
a sani])le of explosive of specified Aveight Avhen it is 
heated in a vacuum at an elevated temperature for 
a limited time. The usual sample is five grams; the 
test is ordinarily run at 100, 120, or 150 C, and the 
duration of the test is usually from tAventy-four to 
forty-eight hours. The apparatus itsed at the ExplosiA^es 
Ilesearch Laboratory differs from that described in 


36 


THE PROPERTIES OF HIGH EXPLOSIVES 


the literature, and the original reports should be eon- 
suited for details of eonstruetioji and operation. 

It is customary to deduct the gas evolved during 
the first ninety minutes of the vacuum stability test 
on the ground that most of it is probably occluded 
gas, and not gas produced by decomposition of the 
explosive. In general, a normal value for the vacuum 
stability test can be established for each explosive; 
larger amounts of gas evolved from subsequent sam- 
ples indicate that they are of inferior quality. Com- 
parisons of one explosive with another on the basis 
of vacuum stability tests are misleading, and often 
there is no correlation between vacuum stability tests 
at 120 C and those at service temperatures ( —40 to 
+60 C). 

Explosion Tempeuatuul 

There is no generally accepted method of determin- 
ing the temperature at which a material explodes. 
Two methods have been used at the Explosives Iie- 
search Laboratory. In the first, five- to ten-milligram 
samples of the explosive are dropped onto the surface 
of a Wood’s metal hath. The initial temperature of the 
bath is 360 C. The bath is allowed to cool and tests 
are continued until the lowest temperature at which 
the sample will deflagrate or explode in five seconds 
is found. The second method was devised to eliminate 
several sources of error in the first procedure. In the 
second method, the sample is placed in a copper tube 
which dips into the AVood’s metal hath. When the sam- 
ple deflagrates or explodes’, the cover is blown off the 
copper tube. This breaks an electric circuit leading to 
an impulse counter and interval timer, thus giving 


an accurate measurement of the time during which 
the cx})losive was heated. The use of the copper cup 
ensures that the sample is in contact with the interior 
of the hath.^“ 

SUHVEILLANCE 

ddie best test for the stability of an explosive which 
has yet been devised, exclusive of actual service, is 
surveillance. A sample of the explosive is maintained 
for a considerable period of time at a temperature as 
high as or higher than it will ever be subjected to in 
service. Portions of the sample are withdrawn peri- 
odically and examined for melting point or vacuum 
stability. The usual surveillance temperature is 65.5 C 
(150 F), although surveillance is occasionally (‘ar- 
ried out at both higher and lower temperatures. Most 
military high explosives will survive surveillance at 
65.5 C for many years, and it can, therefore, be an- 
ticipated that they will be satisfactory for an indefi- 
nite length of time at ordinary service temperatures. 
The most stable explosives tested at the Explosives 
Pesearch Laboratory were TNT and RDX, both of 
which survived without apparent change for over 
three years at 85 C. TNT is molten at this tempera- 
ture. By contrast, some samples of PETN have failed 
in surveillance at 65 C in less than a year and a half. 
Even this surveillance life at 65 0, however, is ample 
assurance of adequate service life. 

Table 2 gives surveillance and vacuum stability 
data on a number of service lillings. 

Special Stability Problems 

There are many special stability problems presented 
by individual high explosives. These problems (for 


Table 2. Surveillance and vacuum stability data on some service fillings.* 


Explosive 

Composition 

Surveillance 

Temp Time 

(C) (months) 

Normal vacuum stability at 120 C 
Gas evolved (cc/5 g/48 hr) 

PETN 


65 

17 to 29 1 

1.0 to 5.0 cc/2.3 g/20 hr 

Pentolite 

PETN/ TNT- 50/50 

65 

29t 

3.0 at 100 C 

Haleite 


65 

33t 

4.5 

TNT 


65 

23t 

0.2 



85 

23t 


RDX 


65 

32t 

0.5 cc/5 g/24 hr at 150 C (f) 



85 

32t 

2.0 cc/5 g/24 hr at 150 C (§) 

Composition A 

RDX/Wax-91/9 

65 

lot 

0.7 

Composition B 

RDX/TNT/Wax-59.5/39.5/1 

65 

39t 

1.0 

Tri tonal 

TNT/Al- 80/20 

65 

25t 

0.2 

Torpex-2 

Comp B/TNT/Al- 70/12/18 

65 

30t 


Minol 

TNT/NH 4 NO 3 /AI- 40/40/20 

65 

17t 

2.0 


*The data in this table are a selection from the data accumulated at the Explosives Research Laboratory. Additional data will be found in references 
17 , 58 - 60 . 

tSamples still in surveillance. 

JRDX made by the direct nitrolysis of hexamine. 

§RDX(B) made by the combination process. 


|•|l>l^:^TTAh 


STABILITY 


37 


example, the 1‘aetors wliieli ailVet the istahilily ut' a 
l>aitieular explosive, the ineetiaiiisin ot' decoinpositiuii 
of a particular ex})losive, and the selection of tests 
which will hest measure the stability of a particular 
explosive) must be studied individually and are not 
amenable to routine testing. Three such special prob- 
lems are considered in the paragraphs Avhich follow. 

(’ertain samples of Pentolite show highly erratic 
behavior on surveillance. As the result of an extended 
study of the reasons for this behavior, it was found 
that the stability of Pentolite is impaired by the pres- 
ence of acid and, to a greater extent, by the presence 
of alkali. Xitrated by-products from the pentaerythritol 
synthesis, e.g., DiPEllX, have no detectable ell'ect 
on the stability of Pentolite. 

Contamination of Pentolite by acid is unlikely if 
the PETX from which it is made has been properly 
stabilized. Contamination of Pentolite by alkali is 
due to the alkali left in the PETX during ordinary 
procedure for the stabilization of the latter material. 
When PETX is stabilized by the addition of solid 
sodium caiTonate to an acetone solution of the explo- 
sive, the PETX will contain about 0.03% of sodium 
carbonate. When sodium carbonate solution is added 
to an acetone solution of PETX, the precipitated ma- 
terial will contain about 0.008% of sodium carbonate. 
The addition of a 1% solution of ammonium carbo- 
nate to an acetone solution of PETX precipitates ma- 
terial which yields the highest quality Pentolite. 

The 100 C vacuum stability test fails to reveal the 
presence of harmful amounts of alkali in Pentolite, 
since the temperature coefficient of the alkali-catalyzed 
decomposition is much smaller than that of the spon- 
taneous decomposition. Nor does the 120 C vacuum 
stability test give useful information about the sta- 
bility of the material; for the results of this test are 
largely determined ])y the amount and location of 
occlusions containing acetone, and these occlusions 
do not impair significantly the low-temperature sta- 
bility of Pentolite.^^’^^ The rate of gas evolution at 
68 C is the best measure of the stability of Pentolite.*^ 

The stability of Haleite, ethylenedinitramine, has 
also been examined in considerable detail. The de- 
composition of Haleite furnishes ethylene glycol, acet- 
aldehyde, and nitrous oxide. When the solid exjdosive 
decomposes between 120 and 150 C, 90% of the de- 
composition products are volatile. The decomposition 
is not gas catalyzed ; the temperature coefficient of the 

®A related report^^ describes the preparation, optical crystal- 
lography, and fusion analyses of pure PETN and DiPEHN, 
together with a phase study of the system PETN-DiPEHN. 


decomposition increases with increasing temperature 
in the range 100 to 145 P, and the rate of decompo- 
sition is increased by the presence of any one of a 
number of inert materials, for example, iron, iron 
oxide, barium sulfate, sand, or activated carbon. 
Large crystals of Haleite decompose more slowly than 
small crystals in the vacuum stability test, whereas 
large samples decompose more rapidly than small 
samples. When Haleite is crystallized, the more acidic 
the solvent the less stable is the product. The 135 C 
thermal stability test, useful with organic nitrates, 
is not useful with Haleite, for this material loses its 
nitrogen as nitrous oxide. The 120 C vacuum stability 
test does give useful results if appropriate precau- 
tions are taken. 

The kinetics of decomposition of four organic high 
explosives have been studied.^® The explosives were: 


Eivonite 


Sixolite 


MNO 


NENO 


^CO 

CH^-CHCH^ONOJ^ 

CH2-C(CH20N0,)2 

I 

CHg CHONO 2 

\cH2-C(CH20N02)2 

C0N(N02)CH3 

C0N(N02)CH3 

C0N(N0.)CH2CH20N0o 

I 

C 0 N(N 0 ,)CH 2 CH 30 N 03 


The investigation was carried out by measuring the 
gas evolved from the explosive. In some runs the 
decomposition was carried to completion, and the 
amount of gas produced per mole of the explosive 
determined. The rate of decomposition of Eivonite 
and Sixolite increases with time; the increase in rate 
with time is greater at moderate (85 to 120 C) than 
at elevated (135 to 150 C) temperatures. At the high 
temperatures the decompositions were followed to 
completion. The increase in rate with time for these 
nitric acid esters may well be due to autocatalysis. 
The possibility has, however, been suggested that 
some if not all of the effect is due to the fact that 
these are explosives with many reactive groups, and 
the appearance of autocatalysis can be produced by 
a multistep decomposition. By contrast, the decompo- 
sition of the nitramines in solution followed a simple 
first order law. The reactions take place at the same 


IViXTTr>KN-J'J.\& 


38 


THE PROPERTIES OF HIGH EXPLOSIVES 


rate wliotlier the explosives are molteu or dissolved in 
TNT. The solid explosive decomposes iiiucli more 
slowly, however, and the acceleration in rate usually 
observed when an explosive is mixed with TNT has 
been correlated with the enhanced rate of decomposi- 
tion in solution as compared with that in the solid 
state. 

The activation energy for the initial decomposition 
of the nitric acid esters was about 50,000 cal per mole, 
whereas that for the nitramines was only about 35,000 
cal per mole. 

2.2 SENSITIVENESS^^ 

New explosives and explosive mixtures are generally 
developed in the laboratory for specihc field uses, and 
must accordingly meet certain requirements of sen- 
sitivity and performance. The ultimate tests of these 
properties are provided, of course, by actual trials in 
the munitions for which the explosives are intended, 
first on an experimental basis at a proving ground, 
and finally in combat. For these ultimate tests there is 
no substitute; but since they are time-consuming, 
expensive, and hazardous, all possible efforts are made 
to screen out, at the laboratory stage, materials which 
appear unlikely to pass service tests. Such laboratory 
screening tests may occasionally pass materials later 
rejected, or may occasionally hold back from final 
tests materials which might have been acceptable; 
nevertheless, their usefulness, within their proper 
domain, is great. The fact that most explosives under 
development are planned as substitutes for ones in use 
permits comparisons to be made between pairs of ex- 
plosives in laboratory tests ; from such laboratory com- 
parisons the suitability of the substitute explosive 
must be inferred. 

^ ^ ^ Sensitiveness Tests at the Explosives 
Research Laboratory 

In laboratory tests of sensitivity, pairs of explo- 
sives are compared by subjecting each explosive to 
stimuli (usually mechanical) of controlled violence, 
under controlled conditions, and comparing their re- 
sponses. When these responses vary only in degree, 
the relative sensitivities may then be at once inferred, 
when account is taken of the statistical nature of these 
responses ; but when the responses differ also in kind, 
then arbitrary decisions concerning the relative liaz- 

•^This discussion is taken from a summary prepared by E. 
H. Eyster. 


ards of the various kinds of respoiise must be made 
if a definite sensitivity comparison is demanded. 

Duo P- W' J-:iG H T I M PA CT T ESTS 

Drop-weight impact tests provide one of the easiest 
sensitivity comparisons which may be made. In such 
tests small samples of the explosives to be tested are 
loaded betAveen a hardened steel anvil and plunger 
(the tooh) and the plunger is then struck by a Aveight 
Avhich is alloAATd to fall through a predetermined dis- 
tance. By carrying out a series of trials at different 
drop heights, the probability of explosion as a func- 
tion of drop height may be explored for the explosives 
to be compared. The 50^ explosion height has been 
used at the Explosives Besearch Laboratory to charac- 
terize the results of such tests, and statistically efficient 
methods have been devised to determine this height 
and to estimate the random errors made in its deter- 
mination. If, then, the 50% explosion height for one 
explosive is shoAvn to be significantly higher than that 
of a second, the first explosive is shoAvn by this test 
to be less sensitive than the second. In this manner 
many explosives may and have been ordered in impact 
sensiiiviiij. It has been found, hoAvever, that the order- 
ing obtained depends upon the exact mechanical de- 
sign of the toots used in the impact machine. About 
a dozen different tool designs liaA^e been studied. Of 
these the folloAA'ing three liaA^e been particularly use- 
ful for testing solids, and haA’e been extensively used 
at the Explosives Ilesearch Lal)oratory. 

Type 3. In this design the explosive is loaded in a 
brass cup, 0.308 in. in inside diameter, 0.01 in. thick, 
and % in. high. The half-inch steel plunger tapers 
to a 0.306-in. diameter cylinder near the tip and fits 
inside the cup. The cup rests on a flat steel anvil. A 
5-kg Aveight and a maximum drop of about 100 cm are 
used Avith these tools. 

Type 5. In this design the explosive is loaded in a 
cylindrical cavity, in. deep and 0.376 in. in diam- 
eter, in the hardened steel anvil, and is covered by a 
sheet of thin tinfoil. The y 2 -in. plunger in this case 
tapers at the end to a 0.375-in. cylindrical section and 
is pressed doAvn on the ex})losive in the cavity. A 5-kg 
AA'eight and a maximum fall of about 100 cm have been 
used Avith this design. 

Type 12. In this design the explosive is loaded on 
a square of 5/0 Flint paper, resting on a l)4-in. hard- 
ened steel flat anvil. The plunger is a fiat I/i-in. cyl- 
inder. A 2y2-kg Aveight and a maximum fall of about 
330 cm liaA^e been used Avith this design. 

'The 1\ype 3 design is suited particularly to the test- 


tOXFIDE^TIAlA 


SENSITIVENESS 


39 


iiig of explosives of sensitivity equal to or greater in tlic apparent sensitivities of all explosives. At the 
than that of Tetryl. The other two designs will fire Ex])losivcs Research Laboratory it is preferred, gen- 
TNT, Composition A, and ammonium picrate. The erally, to make important impact-test comparisons 
sensitivity orderings produced by these three tool with several tool designs; when all agree in ordering, 
designs are not identical, though they do show a the results are satisfactory, otherwise different tests 
gross correlation. Apparently variations of the phys- are appealed to. 

ical conditions (strength of confinement, effect of grit. Some typical results of impact tests with these three 

etc.) during impact do not produce uniform changes tool designs are given in Table 3. 

Table 3. Sensitiveness of high explosives.* 

1 

2 3 



4 5 

6 


Dens. Impact sens. 

Bullet sens. Shell imp. sens. 

Booster 

Explosive 

(g/cc) #3 #5 #12 

LI. (ord) 

No. I.I. (alz) No. F5o(fps) crVto 

sens. 

Aluminized Comp. A 

1.71(p) .. .. 

62 

.. 

.. 


Amatol 80/20 

• • • • • • 

. , 

, , 



Amatol 60/40 

• • • • • • 

• • 

• • 



Amatol 50/50 

1.55(c) .... 

101 

>58 

10 


Ammonium Picrate 

1.55(p) 80 19 

235 

* , 


511204-2 

Baronal 

2.32(c) 84 . . 

, , 

* * 


10||5 

Borotorpex (46/44/10) 1.74(c) . . . . 

• • 




Comp. A-3 

1.61(p) >90 .. 

80 

. ; 


20 4-21115 4-2 

Comp. A-12% Wax 

1.58(p) .... 

108 

• • 



Comp. A/KN08-50/50 1.76(p) 66 . . 

59 

. . 



Comp. B 

1.69(c) >90 26 

82 

50 

579 209 8 


Comp. 02 

1.57(pl) .... 

. . 

, , 



Cyclotol-60/40 

1.69(c) .... 

78 

38 

225 

51125 4-2 

Cyclotol-70/30 

1.72(c) .... 

56 

40 

30 


DBX 

1.76(c) .... 

73 


35 23 

51125 4-2 

Diethylene glycol 






dinitrate 

Liquid . . . . 

, . 

• • 



DINA 

1.58(c) 27 13 

23 

6 

10 


Haleite 

1.76(cr) 65 35 

38 

, , 


5 4* 2ll 20 -p 3 

Ednatol 50/50 

1.62(c) .... 

74(55/45) 69(55/45) 178 

10115 

Ednatol 60/40 

1.62(c) 





Fivonite 

1.59(c) >90 38 

69 

42 

58 

51125 4-2 

RDX/Fivonite 53/47 1.66(c) . . . . 

29 

27 

40 


HBX 

1.73(c) .... 

130 


70 570 411 Average 






of 4 tests 


Hexanitrodiphenyl- 






amine 

• • • • 

, 1 

• • 



Minol-II 

1.71(c) .... 

76 


35 44 828 28 

151110 

MNO 

>90 39 

103 




NENO 

45 .. 

29 




Nitroguanidine 

1.50(p) .... 

>337 




Pentolite 50/50 

1.65(c) 65 31 

38 

19 

220 v^nO 

25 4-31120 4-3 

PEP-2 

1.42(pl) .... 

. . 

. . 



PETN 

1.76(cr) 29 8 

12 

. , 


Fired by 5 4- 3 

Picratol 52/48 

1.63(c) .... 

210 

95 

20 


Picric Acid 

1.60(c) >90 22 

54 

27 

11 

51125 4-2 

PTX-1 

1.68(c) .... 

46 




PTX-2 

1.70(c) .... 

38 

8 

14 


RDX 

1.82(cr) 48 23 

17 



15 4-311104-3 

RIPE 

1.37(pl) .... 

341 




Tetryl 

1.56(p) 56 20 

42 



5 4-21120 4-3 

Tetrytol 75/25 

1.66(c) .... 

70 

43 

40 

25 4-21120 4-2(70/30) 

TNT D-2 

1.55(c) .... 

311 

>85 

20 


Torpex-II 

1.81(c) >90 .. 

78 


32 166 185 9 

51125 4-2 

Tritonal 80/20 

1.75(c) .... 

138 


60 70 509 82 

151110(85/15) 

Tritonal 80/20, D-2 

1.67(c) .... 

271 

, , 

. . 


TNT 

1.60(c) >90 48 

171 

72 

86 Over 1100 

201115 


♦Data from the Explosives Research Laboratory. 



4U 


THE PROPERTIES OF HIGH EXPLOSIVES 


Bvll et- I M rAc;T T es rs 

'ilie bullet-iini)a(T test is performed by loading the 
explosives to be compared into suitable containers and 
llring at them with .30- or .50-caliber bullets (usually 
Ball, M3). AYlien a suitable bullet-container combina- 
tion has been found, the comparison is made with as 
many trials as seem warranted. From the results one 
may deduce whether the explosives display significant- 
ly dilferent probabilities of explosion. This test is 
more difficult to carry out than is the impact test and 
requires much larger samples of explosive, but it is 
also more closely related to real hazards in combat. 
It has been found that the addition of aluminum pow- 
der to explosives changes the nature of their reaction 
to Indlet impact, greatly increasing the chance of a 
mild partial explosion, but apparently decreasing the 
chance of high-order detonation. This makes it rather 
difficult to express sensitivity comparisons between 
aluminized explosives and nonaluminized ones. With- 
in each class, however, comparison may readily be 
made, and these results may be expressed on a numer- 
ical scale as insensitivity indices. The indices for alu- 
minized explosives should not be compared with those 
for ordinary explosives. 

Typical sensitivity indices are given in Table 3. 
The Shell-Impact Test 

There is great need for a test that will give infor- 
mation about the relative sensitivities of dilferent ex- 
plosives when they are loaded in bombs and the boml)s 
are dropped from planes. The large-scale drop testing 
of bombs which should furnish this information is 
extremely expensive if enough tests are made to give 
statistically useful information; and, because of the 
many variables involved (terminal velocity, angle of 
incidence, nature of surface, etc. ) the number of drops 
I’equired in order to secure significant results is very 
large. The shell-impact test was developed to stimulate 
an a small scale conditions existing in the large-scale 
drop tests of bombs. Unfuzed 60-mm mortar shells, 
loaded with the explosives to be compared are fired at 
})redetermined velocities (from 180 to 1,100 fps) 
against heavy armor plate. Testing is continued until 
the 50% ex])losion velocity has been determined with 
suitable ])recision. This test has not been developed 
so far as have the tests described earlier, but it is a 
test which shows sufficient promise to merit further 
develo})ment. 

The Boosteji-Sexsitivity Test 

This test was designed to measure the relative ease 
with which explosives could be brought to full de- 


tonation by boosters and involves festing 1-in. cyl- 
inders 1 in. high with a series of graded boosters. This 
booster series was prepared in the following way. The 
most powerful boosters are 1-in. diameter Tetryl pel- 
lets of 5, 10, 15, 20, and 25 g Aveight; the boosters of 
intermediate power are these same pellets separated 
from the charge by cylinders of Acrawax B 2 cm in 
height ; the least poAverful boosters are the same pellets 
separated from the charge by 3 cm of AcraAvax B. 
Each booster may be identified by stating the Aveight 
of Tetryl and the thickness of Avax : 5 % 3 thus means 
a 5 g booster and 3 cm of Avax. High-order detonation 
is detected by detonating the test cylinders on a y 2 -in. 
steel plate and inspecting the damage. Test results are 
expressed by naming the strongest booster that fails 
to detonate the test cylinder, and the Aveakest booster 
that does detonate it. The booster pair may be abbre- 
viated thus; f 5 -|- 3| 1 10 -|- 3. Naturally, the booster 
sensitivity depends upon the physical state of the 
sample. Cast cylinders are usually less sensitive than 
pressed ones. In a gross sense the results of this test 
also correlate Avith those of impact and bullet tests, 
but there are again exceptions, e.g., Minol-2 has very 
loAV booster sensitivity, although its bullet and impact 
sensitivity seem fairly high. All of these aspects of 
sensitivity must be considered in interpreting small- 
scale tests. 

2 Sensitiveness Studies at the Hercules 
Experiment Station^'"^ 

From duly 1, 1042, until August 31, 1045, under 
Contract OEMsr-710 Division 8 supported an inves- 
tigation of the sensitiveness of high explosives at the 
Hercules PoAvder (hmpany. The Hercules group did 
not have to run routine sensitiveness tests and Avere 
able to devote their entire time to a study of sensitive- 
ness. Their investigation Avas primarily an experimen- 
tal study of the influence of a variety of factors on the 
sensitiveness of explosives to a number of different 
initiating influences.® 

In the investigation a markedly improved friction 
pendulum and a considerably improved minimum- 
priming charge test AA^ere developed. Improvements 
Avere made in the rifle hullet test and modifications 
AA^ere made in the impact test equipment. It is rec- 
ommended, as a result of the investigation, that ncAV 
explosives be subjected to impact tests, to friction- 
pendulum tests, to minimum-priming charge tests, 
and to ride hullet tests; and that the evaluation of 

®This summary is based largely on OSRD-6629. 


k (>\1-ii)i:N TiAi.t 


SENSITIVENESS 


41 


the sensitiveness of tlie explosive and tlie hazards in- 
volved in its use he made from tlie results of the four 
sets of tests rather than from any one test alone. 
Table 4 gives test data on a number of important 
explosives. 

SkXSITIVEXESS to iMrACT 

For most of the work a Bureau of Mines type im- 
pact machine was employed with a maximum height 
of fall of 100 cm and equipped with 1-, 2-, and 5-kg 
weights. This was later supplemented by a larger im- 
pact machine giving heights up to 200 cm. Impacts 
were usually run Avith one of the following hammer- 
and-anvil combinations : 

Design 1 1-in. diameter flat anvil, 0.5-in. diam- 

eter flat hammer. 

Design lA Same, but surfaces roughened by sand- 
blasting with Xo. 30 corundum. 

Design 2 Anvil as in design 1. 0.300-in. diameter 
hammer, explosive placed in a 0.308- 
in. diameter copper cup which rested 
on anvil. 

Design 5 Anvil as in design 1. Explosive placed 
in a 0.30T- by cavity in a 0.5-in. 

diameter by 0.25-in. steel cylinder Avhich 
rested on anvil. Hammer, 0.306-in. 
diameter. 

The designs most adaptable to use for a Avide vari- 
ety of explosives are lA and 5. HoAA'evcr, all four AA^ere 
used rather extensively in addition to one or tAvo 
others. Hammers and anvils were of tool steel hard- 
ened to liockAA’ell C 60. 

One of the most important discoveries Avas the 
clfect of thickness of explosive layer on the sensitive- 
ness results. Actually, the mass of the explosiA^e sample 
is the important variable rather than the thickness. 
Thus, the height of fall is very little affected AAdien 
PETX or nitromannite is precompressed up to 24,000 
psi. Other evidence shoAVs that the mass of the sample 
taken, rather than its volume, is decisive: heavier im- 
pacts are required for larger samples. Hence sample 
Aveights should alAATiys be specified. Tavo samples of 
the same explosiA^e of differing bulk density Avill give 
the same results if their weights are the same but not 
their volumes. For explosives of Ioav melting point 
the effect of quantity of explosive on height of fall is 
small. Apparently the sample melts and enough is 
expelled to give a constant thickness. 

Regardless of the design used (except for very 
rough sand-blasted surfaces) the graph of height of 
fall Awsus AA^eight of explosiA-e sample was always 


linear. A curious fact is the observation that for ex- 
plosives such as FETX and nitromannite the height 
ol' fall ai)parently becomes independent of the Aveight 
as the thickness of the explosiA^e layer on the anvil 
approaches zero. That is, the graphs of height versAis 
quantity of explosive for 1-, 2-, and 5-kg Aveights 
come to a common intercept on the height axis. Thus 
for very thin layers the velocity of the falling AA^eight, 
given by \/2g/i, rather than the energy, becomes the 
controlling factor. Originally Cyclonite did not appear 
to behave like FETX, as the intercepts for the differ- 
ent AA^eights did not come at the same point; hoAA^ever, 
more recent samples of Cyclonite have been found to 
behave in the same Avay as PETX. Generally the re- 
sults obeyed the laAA^ 

M {h — //y) = constant, 

(4/ = mass of falling AA'eight, // = height of fall for 
50% shots, and Ay — the intercept on the height axis 
for zero quantity of explosive.) 

The addition of 5% of grit (Silex — 200-niesh sil- 
ica) increased the sensitiveness of most high explo- 
sives by a factor of 6 to iO. Increased particle size of 
the explosive decreased its sensitiveness. Adiabatic 
compression of the air adjacent to the sample Avas 
Avithout effect. Hardness of the impacting metals and 
rigidity of the anvil are of great importance as sen- 
sitiveness decreases markedly for softer metals or for 
even slight cushioning of the anvil. Initiation of the 
explosive apparently results from the compression of 
the explosiA’e, from frictional effects betAveen individ- 
ual particles, and from floAV across the metal surfaces. 
The most satisfactory hammer-and-anvil combination 
appears to be Design 5 in AAdiich even TXT can l)e 
brought Avithin the range of a 2-kg Aveight on a 100- 
cm machine. 

From a practical vieAvpoint it appears that impacts 
and frictional impacts even betAA^een relatively soft 
metals should be avoided, as should impacts under 
confinement. The presence of finely divided explo- 
siA’es, thin layers, etc., should be avoided as far as 
possible. Considerable hazards exist in the use of 
metals until their hardness becomes less than that of 
annealed copper; the hazaids are markedly reduced 
for lead. 

Sexsitiveness to Friction 

In investigating friction sensitiveness most of the 
Avork was carried out with a modification of the Bu- 
reau of Mines small friction pendulum, but tAVo 
rotating pin arrangements were also investigated. In 


t'ONl'IDKNTIAlTA 


42 


THE PROPERTIES OF HIGH EXPLOSIVES 


the first, a small amount of explosive was mixed with 
Silex (a powdered silica) and ground under a rotat- 
ing pin in a small copper cup. The second rotating- 
pin method involved grinding the explosive between 
a fixed anvil and a rotating pin to which pressure was 
applied with a hydraulic press. It was found that even 
with PETN, it was extremely difficult to cause shots 
with this apparatus, so its use was not further exam- 
ined. 

Because of the difficulties encountered with the 
rotating-pin method, all the rest of the friction work 
was carried out with a modified friction pendulum in 
which a narrow shoe or a ball bearing was used for the 
pendulum bob and fresh metal surfaces were used for 
each trial. By using sand-blasted surfaces it has been 
possible to extend the range of the machine to include 
not only initiating explosives but also explosives as 
insensitive as Tetryl and Composition B. Fresh sur- 
faces are used for each trial. 

In carrying out the friction tests one can use either 
sand-blasted surfaces for the anvil and the pendulum 
shoe, or use smooth surfaces and mix grit with the 
explosive. The pressure exerted on the anvil depends 
on the angle of incidence of the pendulum. It was 
found, however, that the height of fall generally de- 
creased to a constant value when the angle of incidence 
exceeded a certain minimum, generally 2 to 4°, and 
then remained constant over the range tested, usually 
up to 10 to 12°. Loudness of shots is increased as the 
angle of incidence increases and as the area between 
contacting surfaces increases. The effect of increasing 
the pendulum weight is to decrease the height of fall 
continuously as the weight added to the pendulum is 
changed from 1 to 10 kg. 

Bigidity of the anvil backing has little influence on 
sensitiveness. This is in contrast to the results ob- 
tained on an impact machine. Sensitization by grit 
is marked. 

Increasing roughness of the pendulum and anvil 
results in a decreasing height of fall. The sensitiveness 
is independent of the thickness of the explosive layer 
until it becomes less than about 8 mg per square cen- 
timeter, apparently because the excess explosive is 
pushed out of the way by the pendulum so that, in 
effect, thickness is independent of the quantity of ex- 
plosive used in a trial. Sensitiveness is not decreased 
for impacts between hardened steel and soft metals 
until one of the metals becomes softer than annealed 
copper. When both metals are the same there is a 
steady decrease in the hazard as the metals become 
softer. 


Sensitiveness to Glancing Impact 

A sliding rod machine in which a rod with a hemi- 
spherical nose slides down a trough and strikes the 
sample of explosive on an anvil was investigated in 
order to determine its usefulness. In this machine the 
height of fall for hardened steel nosepiece and anvil 
increases as the angle of impact comes closer to the 
vertical. For softer anvils, however, maximum hazard 
seems to occur at an angle of about 65 to 70°. The 
machine does not appear of much utility for military 
explosives less sensitive than Cyclonite, since it was 
not possible to secure audible shots or reproducible 
results with most such explosives. It does offer con- 
siderable utility in assessing the hazards of metals 
and other materials of construction. 

Sensitivi-:ness to Detonation by Initiating 
Explosives 

An improved minimum priming charge test was 
developed. This test is a measure of the minimum 
weight of initiator required to detonate a charge of 
the explosive under study. Previously a primer had 
been used together with an intermediate wafer charge 
when necessary for insensitive explosives; the use of 
the wafer charge made comparisons between sensitive 
and insensitive explosives difficult. By employing as 
the primer a 40/60 mixture of lead azide and PETN 
it was possible to do away with the intermediate wafer 
charge; the lead azide-PETN primer will detonate 
insensitive as well as sensitive explosives. 

Prior to the development of the azide-PETN 
})rimer, the minimum-jiriming charges of a large num- 
ber of explosives, both pressed and cast, were deter- 
mined by using a diazodinitrophenol primer with a 
PETN wafer charge when necessary. A very satis- 
factory correlation was observed between the impact 
sensitiveness as determined in the design 5 machine 
and the minimum priming charge for either the azide- 
PETN primer or the diazodinitrophenol primer with 
PETN wafer. The correlation was l)etter with the 
azide-PETN primer. Since cast explosives are so much 
less sensitive than pressed, it is necessary to compare 
the two types separately. 

Sensitiveness to Bifle Bullets 

Extensive studies were made on various aspects of 
sensitiveness to rifle bullet impact. In these tests the 
container for the explosive was a short piece of pipe 
with a metal plate welded to one end. The explosive 
was then either cast or pressed into this container and 
a disk of steel or other material pressed firmly against 


fcONKrmTNTIAlj 


SENSITIVENESS 


43 


the surface of the explosive. This container was laid 
on its side with its base against a steel block and bul- 
lets were fired into the explosiA^e through the disk 
along the axis of the container. This arrangement made 
it possible to study a number of factors infiuencing 
the production of detonations. The length of the ex- 
plosive column did not greatly affect the sensitiveness 
to bullet impact. Increasing the diameter of the ex- 
plosive column from one inch to two inches appeared 
to increase the proportion of partial detonations to 
complete detonations. 

The infiuence of container material was extensively 
investigated. When only the disk through which the 
bullet penetrated was changed, detonations of 50/50 
Pentolite were produced about as readily with copper 
as with mild steel, but somewhat less so with hard 
lead or Duralumin, and least readily with maple. In 
fact, maple gave about the same results as if there 
were no disk at all on top of the explosive. When, 
however, the base of the bomb was changed and bul- 
lets fired at the explosive with no disk on top of it, 
rather surprising results were obtained. Here the larg- 
est proportion of detonations occurred with maple 
and transite bases, and relatively few detonations re- 
sulted in the bombs with metal bases. It is thought 
this may be because the base of maple or transite was 
easily shattered by the bullet and the explosive forced 
against the steel backing block. When, however, the 
cylindrical casing wall was made of different mate- 


rials with steel base and frontal disk, detonations were 
produced regularly with mild steel, monel metal, or 
Duralumin casings. Detonations occurred less fre- 
quently with yellow brass and copper, not at all with 
maple, and only occasionally with Phenolite or hard 
lead. This indicates that the side wall confinement of 
the charge is an important factor in the production 
of detonations. When the bomb was made entirely of 
a single material, all detonations were produced when 
made of steel and 50% with monel metal, very few 
detonations with Duralumin, yellow brass, or copper, 
and none at all with hard lead or Phenolite. When the 
whole bomb was made of maple there were, surpris- 
ingly enough, 30% detonations which possibly may be 
explained from the shattering action of the bullet on 
the maple base and the consequent impact on the steel 
backing block. 

Maximum sensitiveness in the rifle bullet test 
occurs when the thickness of the metal pierced by the 
bullet before it hits the explosive is about %6-inch. 
Soft-nosed bullets are more effective than armor- 
piercing and the latter are more likely to cause de- 
tonations if made with flattened noses. In small scale 
tests, liners of asphalt or other soft material appeared 
to decrease sensitiveness, although subsequent larger- 
scale tests on full-sized bombs showed little value for 
asphalt liners. There was not much difference in 
rifle bullet sensitiveness of cast explosives and pressed 
explosives at the same density. 


Table 4. Sensitiveness of military explosives. 
Height of fall (cm) necessary for 50% shots 


Design 5 

4 kg weight 

Plane 

sandblasted 

surfaces 

5 kg weight 

Friction pendulum 

30 mg sample 
Sandblasted surfaces 

Hercules 
sliding rod 

Minimum priming charge (g) 

Rifle-bullet test 

2-in. ball 

5 kg weight, 
8® angle of 
incidence 

2 in. X H in. 
ball, 4 kg 
weight, 4° 
angle of 
incidence 

Sandblasted 
surfaces, 45® 
slide angle 
10 lb rod 

30 mg sample 

Diazo initiator 

Pressed 

(d = 1.4 g/cc) Cast 

PETN-lead 
azide initiator 

Pressed 

(d= 1.4 g/cc) Cast 

Reg disk bomb, 
%-m. steel disk 
per cent detonations 

Pressed Cast 

Ammonium 












Picrate 

59 

75 



100 

0.27 




10 


Amatol 50/50 

, , 

, , 

. , 

. , 

22.5 

0.25 

0.57 



0 

0 

Composition A3 

46 

29 


. . 


0.21 

. . 


. , 

, , 


Composition B2 

38 

61 

16 

31 

9.5 

.17 

.27 


.26 


50 

Composition B 

38 

54 

16 

38 

100 

.21 

.33 


.28 


10 

Cyclonite 

23 

25 

18 

25 

10 

.13 

. . 



100 

, , 

DBX 

50 

25 

18 


42 

.19 

.43 



40 

90 

DINA 

8 

71 

11 

. . 

90 

.15 

.29 


.20 


. . 

EDNA 

32 

. . 

22 

27 

30 

.19 

, . 



90 

100 

Minol II 

80 

. , 

26 

, . 

31 

.27 

.85 


.42 


80 

Nitromannite 

15 

12' 

1.1 

3 

5.5 







Pentolite 50/50 

28 

. . 

12 

, , 

9 

.13 

.21 


.16 

20 

100 

PETN 

16 

19 

7.5 

11 

9 

.09 

. . 

.04 

. . 

100 

. . 




44 


THE PROPERTIES OF HIGH EXPLOSIVES 


23 PERFORMANCE? 

At the Explosives Research Laboratory/*'’’^^'^^ where 
essentially all of the work of Division 8® on the per- 
formance of high explosives was done^ two tests were 
used for the laboratory-scale assessment of the per- 
formance or effectiveness of explosives. They are the 
ballistic mortar and plate-denting tests. The quanti- 
ties measured by these two tests are called the power 
and the brisance, respectively. Other measurements, 
such as the determination of the velocity of detona- 
tion, the cavity-charge performance, and the frag- 
ment velocity, are in general related to performance, 
but only the first has been systematically measured 
for many explosives. It is discussed in Section 2.4. 

Ballistic Moetar 

The ballistic mortar has been systematically used 
in the Explosives Research Laboratory to determine 
the power of explosives and explosive mixtures. This 
is a standard instrument and has been described in 
the open literature. With the ballistic mortar one de- 
termines essentially the number of grams of TNT 
required to give the same deflection as 100 grams of 
the exjhosive under test; this value, called the power 
or TV (TNT value), is the expression of the test re- 
sults. These values are generally somewhat different 
from those obtained in the Trauzl Lead Block Test, 
but the method is very convenient, and the results 
seem to be equally valid. Ballistic mortar values are 
particularly useful for new explosive substances. The 
mortar tends to exaggerate the effectiveness of ma- 
terials containing large amounts of ammonium nitrate 
and perhaps does not fairly recognize the improve- 
ment in performance effected by aluminum powder. 
Some typical ballistic mortar values are given in 
Table 5. 

The Plate-Denting Test 

For certain materials, particularly plastic explo- 
sives, the conditions in the ballistic mortar seem to 
be rather remote from the conditions which will be 
encountered in use. For such explosives the contact 
effectiveness, or brisance, seems more important than 
the power. To measure this property we have used 
plate-denting tests, in which an essentially unconfined 
stick of explosive is detonated with its flat end in 

■ ^This section is taken from a summary prepared by E. H. 
Eyster. 

® Division 8 considered only certain aspects of the performance 
of high explosives. The work of Division 8 should be supple- 
mented by an examination of the work of Division 2, which 
was directly concerned with damage from high explosives. 


contact with a heavy steel plate. The depth of the 
dent made in the steel can usually be measured ac- 
curately and has been taken as a measure of the per- 
formance under these conditions. The density of the 
test cylinder is of great importance. For cast or 
plastic explosives this density is usually fixed and 
characteristic of the explosive, but for pressed mate- 
rials it is not determined. Just how to treat such 
materials has not been settled. The practice at the 
Explosives Research Laboratory has been to prepare 
a cylinder of as high density as possible and to test 
it. The results are generally expressed as 100 times 
the ratio of the depth of dent produced by the test 
sample to that produced by a good TNT casting. 

Typical plate-denting values are given in Table 5. 

2 4 VELOCITY OF DETONATIONS^ 

The velocity of detonation is one of the few prop- 
erties of high explosives capable of precise definition 
and measurement. The velocity of detonation can be 
calculated according to the hydrodynamic theory of 
detonation from the loading density, the equation of 
state of the product gases, and other purely thermal 
data.^^ If agreement between the observed and the 
calculated velocities is obtained over a range of load- 
ing densities, the equation of state assumed to apply 
to the product gases can be used with soTue con- 
fidence to estimate quantities such as the detonation 
pressure and the detonation temperature; quantities 
which are of more practical interest than the detona- 
tion velocity, but which are not at present capable of 
direct measurement. 

In order to make the comparison between observed 
and calculated velocities, it is necessary to have de- 
tonation velocity data which are truly characteristic 
of the explosive. The hydrodynamic theory takes no 
account of the rate of chemical reaction in the detona- 
tion wave. Experimentally this finite rate of reaction 
exerts a marked effect on the measured detonation 
velocity unless care is taken to eliminate it. For an 
infinitely fast chemical reaction,- the full thermo- 
dynamic detonation velocity is developed in a charge 
of any size; for a finite reaction rate, however, the 
full velocity is developed only if the charge diameter 
is sufficiently large so that the chemical decomposi- 
tion in the center of the charge is completed before 
the pressure at that point is appreciably reduced by 

^This section is based on a summary prepared by G. IT. 
Messerly. 


{•DNi-mr.xTiATl 


VELOCITY OF DETONATION 


45 


rarefaction waves originating- at tlie surface of the 
charge. 

It is fairly well established that tlie detonative de- 
composition of solid explosives takes place through 
the progressive destruction of surface layers of the 
component particles.-'^'^ If the primary surface reac- 
tion is the rate-controlling step in this decomposi- 
tion, the detonation velocity will, for charges smaller 
than the critical size, depend on the particle size of 
the charge material as well as the diameter of the 
charge. 


Since the reaction rate depends on the detonation 
pressure, and this in turn on the density of the charge, 
the magnitude of the diameter and particle size effects 
are also functions of the charge density, being in gen- 
eral more pronounced in the lower density region. 

In order to obtain data which are theoretically 
significant, effects of both charge diameter and par- 
ticle size must he eliminated. A great deal of the 
experimental work on detonation velocities was direc- 
ted toward this end. Charges of increasingly large 
diameter and decreasing grist size were fired in an 


Table 5. Performance of high explosives.* 


7 

Mortar 
(TXT = 100) 

8 

Brisance 

Dens. Re. Br. 

9 

Det. Vel. 
Dens. Rate 

Dens. 

10 

Frag. Vel. 

Vel. (rel) 
TNT= 100 

11 

Stability 

Vac. Therm. 

Explosive 

5 

142 

1.719 

no 

1.70 

7800 

1.696 

113 



Aluminized Comp. A 

9 

130 



1.60 

5200 

1.655 

73 



Amatol — 80/20 

6 

128 



1.60 

5900 





Amatol — 60 /40 


123 

1.552 

52 

1.60 

6400 



0.87(120) 

N.A. 

Amatol — 50/50 

5 

99 



1.55 

7050 





Ammonium Picrate 

8 

96 



2.32 

5450 



0.00(120) 

N.A. 

Baronal 

3 

129 

1.742 

127 

1.74 

7600 



5.47(120) 

N.A. 

Borotorpex (46/44/10) 

11 

135 

1.611 

126 

1.60 

8200 

1.608 

108 



Comp. A-3 

3 

132 



1.585 

8240 

1.566 

109 



Comp. A— 12% Wax 

2 

98 





1.757 

92 

0.08(120) 

N.A. 

Comp. A/KNO 3 — 50/30 

29 

133 



1.68 

7790 



0.50(120) 

N.A. 

Comp. B 

3 

143 

1.52 

111 

1.58 

7800 





Comp. C-2 

14 

133 

1.716 

132 

1.68 

7790 

1.672 

114 

1.48(120) 

N.A. 

Cyclotol — 60/40 

3 

135 

1.725 

136 







Cyclotol — 70/30 

3 

146 

1.762 

102 

1.66 

6700 



0.60(100) 

N.A. 

DBX 

7 

127 



1.375 

6800 





Diethylene glycol clinitrate 

7 

143 



1.58 

7650 



5.01(100) 


DINA 

34 

139 



1.50 

7550 



3.21(120) 

N.A. 

Haleite 

3 

117 

1.623 

112(52/48) 



1.600 

104(55/45) 0.38(100) 

N.A. 

Ednatol— 50/50 

2 

121 



1.58 

7330 





Ednatol — 60/40 

16 

121 



1.57 

7160 



4.87(100) 

55 

Fivonite 


134 







3.72(100) 

60' 

RDX /Fivonite — 53 /47 


133 

1.730 

106 

1.735 

7400 

1.687 

113 

5.02(120) 


PIBX 

6 

115 









Hexanitrodiphenylamine 

3 

143 

1.719 

NE(c) 

1.70 

6000 



1.48(120) 

N.A. 

Minol— II 

15 

117 



1.45 

6850 



0.84(100) 

N.A. 

MNO 

14 

135 



1.63 

7800 



EC-5hr(100) 

50' 

NENO 

3 

104 



1.50 

7060 





Nitroguanidine 

31 

126 

1.662 

121 

1.63 

7450 

1.632 

108 

2.10(100) 

45' 

Pentolite — 50 /50 

2 

115 



1.42 

7540 



0.0(100) 

100' 

PEP-2 

34 

145 



1.60 

7920 



2.79(120) 

135' 

PETN 

3 

100 

1.630 

100 

1.625 

6915 

1.618 

99 



Picratol — 52/48 

13 

112 



1.60 

7080 





Picric Acid 

3 

132 

1.684 

127 



1.644 

111 



PTX-1 


138 

1.712 

141 

1.685 

7900 

1.676 

118 



PTX-2 

ca.lOO 

150 



1.60 

8235 



0.38-24(150) 

N.A. 

RDX 

3 

118 

1.37 

85 

1.35 

7320 

1.395 

102 

0.14(120) 


RIPE 

51 

130 

1.592 

115 

1.55 

7375 





Tetryl 

3 

122 

1.660 

118 







Tetrytol — 75/25 

3 

100 

1.550 

96 

1.57 

6800 

1.544 

94 



TNT D-2 

11 

134 

1.829 

120 

1.80 

7530 

1.768(41/41/18) 116 

0.64(120) 

N.A. 

Torpex — II 

3 

124 

1.753 

93 

1.76 

6770 

1.82(70/30) 97 

0.10(120) 


Tri tonal — 80/20 

3 

123 

1.667 

85 

1.68 

6560 

1.642 

98 



Tri tonal — 80 /20, D-2 

(100) 

1.602 

(100) 

1.60 

6850 





TNT 


*Data from the Explosives Research Laboratory. 


(n7iri'il)irxTl.\l7\ 


46 


THE PROPERTIES OF HIGH EXPLOSIVES 


effort to demonstrate that the detonation velocities 
finally obtained were truly invariant to these specific 
infiuences. 

The velocity work was performed with a rotating 
drum camera with a speed of 240 meters per sec- 
ond.3-'5*36 camera consists of an aluminum alloy 
drum (in the shape of a shallow angel food cake pan) 
which carries on its inner circumference a meter 
length of 35-mm film. The drum is driven by a 30- 
rpm, 2-hp synchronous motor through an 8/1 speed 
increase!’. Motor, speed increaser, and drum are in- 
closed in a 24-in. diameter pipe which is evacuated 
to 10-cm mercury to decrease the windage on the 
drum. The drum rotates in a vertical plane, and the 
image of a vertical cylindrical column of explosive is 
formed on the film on the inner circumference of 
the drum by means of an /2.0, 5-in. lens and a right 
angle prism. A 0.002-in. slit at 0.025 in. above the 
moving film cuts off all the image of the explosive 
charge except a narrow central portion, and thereby 
greatly increases the time resolution of the camera. 

The explosive charge is fired in a light-tight, bomb- 
proof chamber, and viewed by the camera thru 314 
inches of bullet-resisting glass. The detonation wave 
initiated at one end of the explosive charge is self- 
luminous, and the combined motion of the image of 
the detonation wave across the film and the longi- 
tudinal motion of the film produce a slanting line 
whose slope is simply related to the detonation wave 
velocity. 

The first work done with this equipment furnished 
a variety of information on the nature of the detona- 
tion process. It was found that the luminosity of a 
detonating charge originates mainly in the intense 
shock wave produced by the detonation in the sur- 
rounding atmosphere.®^ 

Various atmospheres differ markedly in their light- 
emitting character, an observation which led to the 
development of the explosive flash photography tech- 
nique.®® The duration and intensity of the luminous 
radiation emitted by detonating explosives is altered 
markedly by the ])rescnce or absence of a transparent 
covering on the charge, and by the spacing between 
such a covering and the surface of the charge. These 
results showed that the width of the luminous zone 
in detonating explosives is not a measure of the width 
of the reaction zone as had been sometimes assumed. 
As a matter of fact, later studies have shown that 
this statement is still true when the shock light is 
eliminated, and the radiation originating only within 
the detonating explosive is examined.®^ 


The first detonation velocity results obtained with 
this equipment appear in reference 40. Most of the 
compounds reported were subsequently reinvestigated 
and their detonation velocity curves revised upward 
when it was found that maximum rates had not been 
attained.^^’^® The general conclusions arrived at in 
reference 40 have not been invalidated, however. The 
detonation velocities of most explosives are linear 
functions of the charge density in the density range 
0.8 to *1.6, with a slope which averages 3,500 meters 
per second j^er density unit. The charge diameter and 
particle size effects are most serious in the lower 
density range, below 1.2, where larger diameter 
charges, and finer grist charge material are necessary 
to obtain the thermodynamic maximum velocity than 
for the more densely packed charges. The belief that 
high bri sauce is necessarily an attri])ute of high de- 
tonation velocity was shown to be not generally true. 

A summary of all the detonation velocity data 
obtained at the Explosives Research Laboratory to 
the time of its closing is given in reference 41. Detona- 
tion velocity data for most of the common explosives 
are reported in considerable detail. For most of the 
explosives studied, it is believed that the curves given 
in that report approach closely to the full thermody- 
namic rate. A selection of the data is given in Table 5. 

Attempts have been made to obtain an equation of 
state which would satisfactorily represent the experi- 
mental detonation velocity data for different kinds 
of explosives over a range of charge densities.^'*’'*''’’ 
The experimental data used both in determining the 
parameters of the equation of state, and in testing 
the resulting equation were subsequently found not 
to represent the maximum velocities of the explosives 
considered. These data were from reference 40, and 
previous interim reports; and the rather indifferent 
results of the theoretical treatment may be attributed 
mainly to inadequacy of experimental data on which 
it was based, although there is also some question as 
to whether the form assumed for the equation of 
state is entirely correct. This subject could profitably 
be reconsidered with the newer velocity data now 
available. 

In addition to the explosive compounds and mix- 
tures which show the usual linear density-velocity 
relation two reports have treated the abnormal be- 
havior of explosives containing ammonium nitrate^® 
and of mixtures of ammonium picrate of different 
grist sizes.^^ The nitrate explosives show a normal rate 
in the low-density range and an abnormally low rate at 
higher density, and thus constitute an exception to 


HEATS OF COMBUSTION 


47 


the usual case of uiaxiiuum deviation from thermo- 
dynamic rate at low-charge density. A mixture of 
ammonium picrate of fine and coarse grist size was 
found to detonate at a lower rate than either the fine 
or coarse grist material alone. No satisfactory ex- 
planation of either phenomenon has been advanced. 

Most of the detonation velocity studies were, as 
mentioned above, directed toward obtaining the true 
thermodynamic velocity of the various explosives. 
However, some work was done on a systematic study 
of the rate-diameter relationship which would permit 
an estimation of the detonation reaction zone length 
according to the theoretical developments of Jones 
and Eyring. The first results of this study have been 
reported.^* Further studies would be very helpful in 
elucidating the nature and mechanism of the de- 
tonation process. For this purpose, however, it would 
be well to review the experimental procedure used in 
both the preparation of the charge and in the meas- 
urement of the velocity; since for the velocity-dia- 
meter studies to be most useful, the maximum ex- 
perimental precision is required. In this connection 
it should be noted that the velocity data reported by 
Cybulski from the Safety in Mines Eesearch Station 
at Buxton in England show considerably greater re- 
producibility than do the Bruceton data. It would be 
useful to investigate the apparatus and methods of 
Cybulski before further extensive velocity work is 
undertaken. 

In addition to the reaction zone length studies 
there are reported in reference 48 the results of 
measurements of the detonation velocity of insuffi- 
ciently boostered cased charges, which were under- 
taken in an attempt to determine the effect of low- 
order detonation on the fragmentation of the shell 
case, and studies on the steady-state shape of the 
detonation wave in various cylindrical explosive 
charges. 

The significance of a number of experiments on the 
detonation velocity close to the point of initiation 
has been considered.^®’^® 

25 HEATS OF COMBUSTION 

The heats of combustion of some fifty nitrated 
organic compounds have been determined by burning 
the compounds in oxygen in a constant-volume cal- 
orimetric bomb. The accuracy of the combustion tech- 
nique is better than 0.1%; errors due to impurities 
in the samples may be considerably larger, however. 
From the heats of combustion, the heats of formation 


were calculated; and, for those compounds of par- 
ticular interest, the velocities of detonation were cal- 
culated according to the procedure described in ref- 
erence 33. 

Some preliminary rules wer(} developed for pre- 
dicting the heat of formation of nitrated organic 
compounds. An example will illustrate the procedure. 
The heat of formation of nitroethane, CHgCHgNOg, 
is — 33 kcal per mole. The heat of formation of 
ethane, CH3CII3, is — 22 kcal per mole. The differ- 
ence, — 10 kcal per mole, is the change in the heat 
of formation accompanying the replacement of an 
aliphatic hydrogen atom by a nitro group. Similarly, 
the changes in the heat of formation accompanying 
( 1 ) the replacement of a hydroxyl hydrogen atom 
by NO2 (OH — > ONO2) is -\-25 kcal per mole; (2) 
the replacement of an aliphatic amino hydrogen atom 
by NO2 ( — Nil — > — NNO2) is — 7 kcal per mole; 
(3) the replacement of an aliphatic amino hydrogen 
atom by NO2 when the amino group is attached to a 
phenyl group (CgH^NH — ^ C6H5NNO2) is -fl7 
kcal per mole; and (4) the replacement of an amido 
hydrogen atom by NO2 (CONH— >'C0NN02) is -(“ 18 
kcal per mole. Replacement of an aromatic hydrogen 
atom by a nitro group is not amenable to such simple 
treatment. 

In a later investigation^- the heats of combustion 
of some twenty organic explosives were determined. 
44ie accuracy of the determinations was at least equal 
to that of the earlier work, and, since the purity of 
the samples was greater, the results are believed to 
be more reliable. Heats of combustion of eight exten- 
sively used explosives are given in Table 6. For 
experimental procedures and for results with the 
other sixty-odd explosives whose heats of combustion 
have been measured, reference should be made to the 
original reports. 


Table 6. Heats of combustion. 


Explosive 

Heat of 
combustion 
Molecular (kcal/moleat 
weight 1 atmosphere) 

1. Ammonium picrate 

2. Diethanolnitramine dinitrate 

246.14 

674.76 

DINA 

240.14 

573.69 

3. Haleite (ethylenedinitramine) * 

150.05 

369.7 

4. Hexanitrodiphenylamine hexanite* 

439.04 

1310.6 

5. Nitroguanidine 

104.07 

207.15 

6. Picric acid 

229.12 

611.93 

7. Tetryl 

287.15 

836.78 

8. TNT 

227.13 

814.30 


*Data for compounds 3 and 4 are taken from OSRD 702.^1 Data for 
the other compounds are from OSRD 5306. 




48 


THE PROPERTIES OF HIGH EXPLOSIVES 


26 IDENTIFICATION AND ANALYSIS 

Four methods were applied to the analysis and 
identification of high explosives: color tests, polaro- 
graphy, microscopy, and chromatography. Chroma- 
tography was used particularly with EDX and related 
compounds; this application was discussed in Section 
1.2. Microscopy as applied to individual high ex- 
plosives has been mentioned in Sections 1.2, 1.3, and 
1.4. The general applications of microscopy to high 
explosives and boosters are discussed below; applica- 
tions to primer compositions are considered in Cfiiap- 
ter 7. 

The most widely applicable and simplest analyti- 
cal procedure developed consists of eleven color tests 
which permit identification of sixteen well-known 
high explosives. The tests, which require only the 
simplest of apparatus, are applicable in the field as 
well as in the laboratory. The procedure is written 
in such a way as to enable the tests to be used by 
nontechnical personnel. The tests are also useful for 
the identification of eight widely used binary explo- 
sive mixtures; this, however, requires judgment and 
ingenuity on the part of the operator in selecting the 
proper order of application of the tests and in in- 
terpreting the results of the tests.^^ 

An attempt was begun in the spring of 1943 to 
evaluate the usefulness of the polarograph as an ana- 
lyti(‘al tool by a study of the polarographic behavior 
of some simple aromatic nitro compounds and of 
'rN4', Tetryl, and picric acid. It was concluded that 
it would be possible to determine small amounts of 
the highly nitrated compounds when they were mixed 
with large amounts of less highly nitrated materials, 
hut the reverse is generally not possible. Further, and 
more discouraging, it was not possible to distinguish 
with sufficient accuracy between two compounds of 
the same degree of nitration, for example, TNT and 
picric acid. C^onsequently the work was discon- 
tinued.^"^ ^luch more success attended the investiga- 
tion of. primer mixtures which is described in Chap- 
ter 7. In the application of microscopy to the iden- 
tification and analysis of explosives, thirty-two high 
explosives and boosters, selected after consultation 
with the Services, were examined as pure individuals 
and mixtures. Two methods were developed for the 
analysis of these compounds.®^ 

The first procedure is based upon the classical 
methods of optical crystallography. It requires that 
the analyst have available complete data on the crys- 
tallographic ])roperties of the compounds which are 


likely to be encountered in an unknown sample. Com- 
parison of the crystallographic properties of the con- 
stituents of the unknown sample with those of known 
compounds is sufficient to establish the composition 
of the sample. All the crystallographic data on mili- 
tary explosives necessary for analysis by the optical 
crystallographic method are presented in I’efer- 
ence 55. 

The utility of the optical crystallographic method 
for analyzing simple or mixed explosives suffers from 
the fact that it is slow. Determination of the complete 
optical crystallographic properties of an organic com- 
pound may require anywhere from a few hours to a 
few days. Further, it requires that the analyst have 
expert training in optical crystallography. 

The second procedure for the microscopical analysis 
of high explosives is the method of fusion analysis, 
which is not subject to the limitations noted for the 
optical crystallographic method. The fusion method 
also makes use of microscopical techniques but it can 
be employed l)y the average analyst, after a brief 
period of instruction, and permits a very rapid 
analysis with a few milligrams of the sample. The 
basis for the method was established by Lehmann in 
1891 when he showed that an organic compound 
crystallizes from its own melt in a very characteristic 
fashion.'"’*^ Further work in this field by McCrone had 
shown that the technique of fusion analysis is a most 
useful analytical method for certain types of organic 
compounds, particularly for some high explosives."’^ 

The method of fusion analysis is the observation, 
usually with the microscope, of the behavior of an 
organic compound when heated slowly on a micro- 
scope slide under a cover glass up to its melting point, 
followed by slow cooling to room temperature. Dur- 
ing this process it is usually possible to observe so 
many characteristic properties of the compound that 
identification may be established within a few min- 
utes. 

Observation of the properties of the crystal-front 
may often be facilitated by carrying out a mixed 
fusion of the sample with thymol. By this procedure 
rapid crystallization is retarded and the crystal-front 
is stabilized for a more leisurely examination. Other 
visible phenomena which may occur in the course of 
the fusion analysis are frequently useful in identify- 
ing the material. These include volume changes in 
cooling with the formation of characteristic shrink- 
age cracks, color and pleochroism, twinning, poly- 
morphic transformations, and anomalous variation in 
polarization colors. 


IDENTIFICATION AND ANALYSIS 


49 


With the addition of a few modifications, the tech- 
nique of fusion analysis has been successfully applied 
to the examination of more than forty high-explosive 
compositions which include the following: Alumatol, 
Amatex, Amatol, Baronal, Compositions A, B, and C, 
Ednatol, Ednatal, Minol, Minex, Pentolite, Pentonal, 
Schneiderite, Tetratol, Torpex, Trimonite. 

In addition to obtaining information regarding 


the qualitative composition of the mixture it is fre- 
quently possible by microscopical methods to estab- 
lish whether the sample is uniform in composition; 
whether it has a surface coating of wax, graphite, 
or the like ; and whether the sample is cast or pressed. 
In addition the purity of the individual components 
may be assayed and the approximate percentage com- 
position of the mixture may be determined. 


Chapter 3 


APPLICATIONS OF HIGH EXPLOSIVES 


I N THIS CHAPTER are considered a variety of specific 
applications of high explosives. Most of these ap- 
plications (Sections 3.1 to 3.6) utilize the shaped- 
charge effect, and an understanding of them will be 
helped by a carefnl study of Chapter 4, in which 
fundamental work on shaped charges is described. 
In addition there will be found in Sections 3.7 to 
3.10 descriptions of such diverse topics as an im- 
proved hand grenade, explosive streamers, liquid ex- 
plosives, and a procedure for increasing the bright- 
ness of shell bursts. 

3 1 SHAPED-CHARGE BOMBS ^ 

Since early in World War II there has been in- 
terest in the possibility of using the cavity effect in 
a large bomb for attack on massive targets. The tar- 
gets most often considered were the heavy concrete 
submarine pens installed by the Germans at several 
jilaces along the French coast, for these structures 
had proved to be invulnerable to attack by conven- 
tional and available bombs. However, two factors 
tended to make the use of cavity-charge bombs un- 
attractive. One was the fact that, while the jet from 
such a bomb would have great penetrating power, it 
was problematical how much damage the jet would 
do to installations beyond the heavy concrete protec- 
tion; the other was the necessity for scoring a direct 
hit if the jet was to have any chance of accomplishing 
its mission. Since the installation of a cavity in the 
nose of a bomb reduces its explosive capacity by 20 
to 30 per cent, it was argued that all bombs so modi- 
fied would suffer a loss of this amount in general 
blast effectiveness, while only a very small percentage 
would actually utilize the penetrating power of the 
jet. As a result of these considerations, development 
of shaped-charge bombs proceeded very slowly, al- 
though a few were constructed and tested. 

In the fall of 1944, the Navy became interested in 
using shaped-charge bombs against warships. While 
the force of the arguments just mentioned was rec- 
ognized, there were two reasons why the point of 
view had changed somewhat. As a result of experi- 
ence with the bazooka and other shaped-charge de- 

^This section is taken from a report prepared by D. P. 
MacDougall.b2 


vices, it was realized that most tanks put out of ac- 
tion by such weapons were damaged by the burning 
of the fuel supply or by an explosion of the ammuni- 
tion caused by the jet rather than by direct mechan- 
ical action of the jet. It seemed reasonable to con- 
sider a warship as similar to a tank but on a larger 
scale. Although it is undoubtedly true that putting 
a hole through the decks of the ship would not put it 
out of action, an accompanying ignition of the fuel 
supply or explosion of the magazine might well do so. 
Furthermore the development of guided missiles had 
been proceeding successfully, and, by the use of a 
guiding device such as Razon, a high percentage of 
hits could be anticipated even against such a small 
target as a ship. As a result of considerations such as 
these the Navy requested that shaped-charge bombs 
in a variety of sizes be developed and procured on 
high priority. The highest priority was given to the 
1,000-lb size since, by making it ballistically equiva- 
lent to the 1,000-lb GP bomb, it would be possible to 
equip it with guiding attachments which were already 
developed. 

By agreement among representatives of the Navy 
Bureau of Ordnance, the Army Ordnance Depart- 
ment, and NDIIC Division 8, the Ordnance Depart- 
ment undertook the procurement of a number of 
shaped-charge bombs in all sizes from 100 to 2,000 
11), using 60-degree drawn steel cones for the cavity 
liners. The Explosives Research Laboratory [ERL] 
of Division 8 undertook to carry out small-scale tests 
of various designs of bombs against various model 
ship targets and to design and procure bombs in the 
1,000-lb size, using formed and welded 45-degTee 
steel cones as the cavity liners. It was felt that 45-de- 
gree cones might have advantages, but that they 
could not be drawn easily. The Naval Proving Ground 
at Dahlgren agreed to test the full-scale bombs by 
firing them statically against spaced armor plate tar- 
gets representing ship decks. 

It had been hoped and expected when the program 
was started that the jet from the 1,000-lb bomb 
would perforate all the decks of a Japanese battleship 
and still have sufficient residual force to ignite fuel 
oil or explode ammunition. It was realized, however, 
that it is difficult to predict with any kind of preci- 
sion the performance of a shaped-charge munition 


50 


SHAPED-CHARGE BOMBS 


51 


against such a complicated spaced plate target as a 
warship, although its performance against a single 
massive plate could be estimated very well. Small- 
scale iVio and %) tests carried out at ERL showed 
that the 1,000-lb shaped-charge bomb could be ex- 
pected to defeat the deck system of a battleship if 
the bomb missed the superstructure and the jet had 
to penetrate only through the main decks. There was 
not much margin, however, and if the tests were carried 
out with the bomb separated from the main deck sys- 
tem by the three light decks of the superstructure, 
success could not be achieved. The amount of steel 
in the superstructure is quite small (three decks, 
each of V 2 -iii. mild steel), but if the bomb detonates 
on top of the superstructure the jet must travel 24 
ft through air before it has a chance to work on the 
main part of the target. Although the performance 
of a cavity charge improves as the stand-off is in- 
creased from zero to two or three calibers, at greater 
stand-offs the performance decreases, presumably due 
to dispersion of the jet. Even the 2,000-lb size when 
tested on a model scale could not defeat the battle- 
ship target with superstructure. 

The fuzing of a shaped-charge bomb presents a 
serious problem. In order to have any cavity action, 
detonation must be started at the rear of the charge. 
However, the standard tail fuzes are not fast enough 
to detonate the bomb with sufficient stand-off. In 
fact their use would result in detonating the bomb 
at zero stand-off or even with considerable distortion 
and crushing of the cavity liner. Two methods were 
considered for fuzing these bombs. One, adopted by 
the Army Ordnance Department, consisted of run- 
ning Primacord from a nose fuze, set for superquick 
action, back through a central pipe to a booster at 
the rear of the charge. The other method, used in the 
bombs procured by the Explosives Research Labora- 
tory, consisted of attaching a small (1-in. diameter 
by 2 V 2 in. long) shaped charge to a standard nose 
fuze (M103) and allowing the jet from this small 
shaped charge to shoot down a central pipe and 
strike a tetryl booster located near the rear of the 
bomb. The standard M103 fuze was used as the basis 
for this point-initiating, tail-detonating shaped- 
charge fuze not by choice, but because it was avail- 
able. However, this fuze is very massive, and its use 
places several inches of metal in the path of the jet, 
the equivalent of adding several inches to the target. 
All ERL bombs tested were detonated by means of 
such a shaped-charge unit, which functioned properly 
every time. The Army bombs were detonated with the 


Primacord arrangement, which also functioned per- 
fectly. The shaped-charge fuze makes loading and 
assembly somewhat easier than does the Primacord 
fuze, but care must be taken in cutting threads, etc., 
so that good alignment is obtained. Alignment is not 
so important with the Primacord fuze. 

The ERL 1,000-lb bombs contained 45-degree steel 
cones having a wall thickness of V 2 in. These cones 
were made by forming in three longitudinal sections 
and then welding the sections together in a jig. The 
first cones made were annealed after welding but 
were not otherwise treated. Later bombs contained 
cones which had been formed from heavier plate, and 
which were then machined on a lathe to very close 
tolerances. The small number of tests conducted 
failed to reveal any significant difference in the per- 
formance of the two, but from other work we feel 
that it is worth while to machine the cones and obtain 
near geometrical perfection. 

AN-M65 1,000-lb GP bomb cases were cut apart 
10 in. back from the nose, and the cones were welded 
in place. The base of the cone was thus about 10 in. 
from the nose of the bomb. The bombs were loaded 
with about 430 lb of Composition B. This represents 
a 28^ decrease in the load of 595 lb of Composition 
B contained in the standard AN'-M65 1,000-lb bomb. 

Full-scale 1,000-lb bombs procured both by the Ex- 
plosives Research Laboratory and by Army Ordnance 
were tested statically at Dahlgren against target plate 
arrangements representing a battleship, both with 
and without superstructure. In some of the tests, the 
space representing the hold of the ship contained 
drums of diesel oil ; in others this space contained 
bombs loaded with cast TNT. Against the target 
without superstructure, the results were generally suc- 
cessful; that is, the target was defeated and the oil 
set on fire or the bombs exploded. In agreement with 
the results of the model tests, the bombs could not 
defeat the target with superstructure. This is a very 
serious drawback to the effectiveness of these bombs, 
since over two-thirds of the deck area is covered by 
superstructure. In agreement also with the small- 
scale test results, the 2,000-lb shaped-charge bomb 
was ineffective against the target with superstructure. 

By the time a limited number of bombs had been 
tested at Dahlgren, the Japanese Navy had just about 
run out of ships, and the ending of hostilities soon 
afterward made it unnecessary to decide upon the ad- 
visability of producing large numbers of shaped- 
charge bombs. Despite the fact that this type of bomb 
did not prove to be so effective as had been hoped in 


52 


APPLICATIONS OF HIGH EXPLOSIVES 


leriiis of amount of |Hmetration ac'liieved, it was very 
successful in setting oil' explosives and in igniting 
fuel oil when the jet could get through tlie protect- 
ing plates. This weapon should receive further con- 
sideration before a final decision is made as to its 
usefulness. 

A related development involves the addition of a 
shaped-charge head to a semi-armor-piercing honih. 
In this Aveapon the shaped-charge is expected to do 
part of the job of penetrating the armored target. 
From the results of scale tests it Avas concluded 
that the addition of a shaped-charge head to the 500-lb 
SAP bomb AA^ould enable the AA^eapon to penetrate 6 
in. of homogeneous armor at a striking velocity of 
750 f})s as opposed to a penetration of 2.5 to 3 in. 
for the unassisted bomb. The chief Aveakncss of the 
Ijomb Avould be its relative inelTectiveness against 
spaced armor, a Aveakness it shares Avith the bombs 
described earlier.^ 

32 ANTISUBMARINE SHAPED- 

CHARGE 

The effectiveness of the Avarfare Avagcd liy Allied 
})lanes against German submarines early in World War 
IT Avas impaired by the difficulty of making hits Avith 
single bombs or sticks of bombs dropped in a line 
pattern and by the defense against imderAvater blast 
provided by the saddle-tank construction of the sub- 
marines. With the adA^ent of applications of the hol- 
loAv-charge principle it immediately became of in- 
terest to design a small bomb AAdiich Avonld defeat the 
saddle-tank defense system of a submarine by punch- 
ing a hole all the Avay through it into the pressure hull. 
The probability of effective attack AA^ould be greater 
Avith small bombs because more of them could be car- 
ried and more dropped in a single attack. 

Late in 1942 the National Defense Research Com- 
mittee Avas asked by the Bureau of Ordnance, Navy 
1 )e])artment, to undertake the design of a holloAA^-charge 
bomb for use against submarines. The bomb aauis to be 
the smallest one A\ffiich Avould defeat a specified target 
Avhich Avould simulate a saddle-tank defense system. 
It AAuis ho])ed that the bomb Avould be small enough to 
be clustered into groups of 25 to 50 per 500-lb unit. 

At tbe time the request for this boinl) Avas made, 
studies of the performance of shaped charges under 
Avater had not been made, althougb the Navy Depart- 
ment had conducted a feAV unsuccessful trials Avith 

'^This section is taken from a report prepared by C. O. 
Davis. Further data will be found in References 4-10. 


holloAv-charge l)oml)s designed by tbc U. S. Ordnance 
Company and loaded at the Eastern Laboratory of the 
dll IVit Company late in 1941. It Avas therefore nec- 
essary for the NDIvC to investigate cavity shape, lin- 
ing material, high explosive filler, charge dimensions, 
and the like before designing the bomb. 

The full-scale target proposed by the Bureau of 
Ordnance comprised a pair of parallel steel plates 
Avith 36 in. of Avater betAA'een them. The first plate, 
representing the skin or saddle-tank shell, Avas of 
V 2 -iii. mild steel. The second plate, representing tbe 
pressure hull Avas of %-in. high-tensile steel. The bomb 
Avas expected to defeat this target in static tests, Avith 
the bomb nose in contact Avith the y 2 -in. plate, and 
the bomb axis pitched at an angle of 45° to the planes 
of the plates. The jet from the homb aauis expected to 
perforate both plates, making a 1- to ll^-in. diameter 
bole in the 1-in. plate. The actual Avater-traA^el dis- 
tance of the jet, Avitli the plates 36 in. apart, Avas 48 in. 
The test AA'as ahvays run Avith a 50-in. Avater-travel dis- 
tance. Since the %-iii. high-tensile steel Avas difficult 
to obtain, 1-in. mild steel Avas generally used as the 
second plate. 

It Avas necessary to have tbe stand-off, or free space, 
betAveen the holloAv in the nose of the explosive 
charge and the end of the bomb nose, as short as pos- 
sible, and to weight the Avails around this space heaA^- 
ily Avith steel in order to keep the center of gravity 
of the bomb far enough forAvard for aerodynamic and 
hydrodynamic stability. With the stand-off thus lim- 
ited to about one-half a caliber, the best shape of cav- 
ity for deep penetration proved to he a cone of about 
45° included apex angle, lined Avith copper or steel. 
The preferred method of cone manufacture Avas by 
stamping flat sheet of the same thickness as the fin- 
ished cone, using a series of dies of decreasing blunt- 
ness and constant surface area. For experimental pur- 
poses a satisfactory method of hand manufacture was 
developed AAdiich did not require dies. Plate of proper 
thickness Avas cut to pattern, bent to a conical shape, 
AA^elded along one seam, and heat-treated. 

The smallest bomb AAdiich Avould dependably defeat 
the target Avas about 6 in. in diameter, and contained 
50/50 Pentolite or 60/40 Cyclotol as filler. Alumi- 
nized explosives Avere evaluated and found to behave as 
if the aluminum Avere inert. 

The preferred cone, explosive-container shape, etc., 
AA^ere incorporated into the shaped-charge antisub- 
marine bomb by NDRC, Division 3. Cluster frames, 
fuze, and scatter mechanism AA^ere developed by Divi- 
sion 6 Avith some assistance from Division 8. A sketch 


ANTISUBMARINE SHAPED-CHARGE FOLLOW-THROUGH BOMB 


53 


of (ho l)()inl) is shown in Figure 1. The finished bond) 
had the following eharaeteristies : 


Bomb case diameter 
Cone base diameter 
Cone angle 
Cone wall thickness 
Cone material 

Cone manufacture 
Explosive 

Explosive charge length 
Explosive charge weight 
Bomb length 
Bomb weight 


0.00 in. 

5.85 in. 

45° 

0.185 ± 0.020 in. 
Mild steel 

(Armco to SAE 1020) 
Cold stamping 
00/40 Cyclotol 
12 in. 

12.5 in. 

22 in. 

38 lb 



This bond) dofoatod the test target when the latter 
was wholly in air, partially submerged, or under water 
at various de})tlis; that is, at conditions simulating a 
surfaced, diving, and submerg('d submarine. The liole 
formed in the 1-in. or pressure-hull plate was a clean, 
nearly round hole 1 to IV 2 in. in diameter with no 
evidence of cracking or splitting of the target. The 
bomb gave highly reproducible penetration, and had 
a small but detinite margin of superiority over the 
target. 

Approximately 3,000 bombs were fabricated by 
NDRC^, Division 6, and loaded at Delaware Ord- 
nance Depot, Pedricktown, NeAv Jersey, under the 
joint auspices of Division 6 and Division 8, for tests 
by the Navy Department. Delays encountered in the 
development of first the scatter mechanism and later 
the fuze prevented use of the bomb in World War II. 
None of the bombs was ever tested against a sub- 
marine. 

With ]io change in shape and little change in 
weight, the bomb could be improved for attack on 
the type of target used in the development Avork by 
(1 ) replacing the steel cones by copper cones; ( 2 ) re- 
placing the 60/40 Cyclotol by the special high-density 
70/30 Cyclotol furnished by the Holston Ordnance 
Works. 

The probable effectiveness of the shaped-charge anti- 
submarine bomb against the German submarines of 
World War II is highly conjectural. A statistical anal- 
ysis of each of the various types of submarines as 
targets AAmuld have to be made to determine the prob- 
ability of a perforation of the pressure hull on any 
givem hit by a bomb capable of defeating the target 
used in the development. In the event of a hit result- 
ing ill a pressure-hull perforation, one must further 
knoAv Avhat effect the perforation Avill have on the 
operation of the submarine. 

It is believed that the shaped-charge design incor- 
porated into the antisubmarine bomb could conve- 
niently and very effectively be carried into bombs of 
much larger size. Depth of penetration scales approxi- 
mately in direct proportion to diameter. 

33 ANTISUBMARINE SHAPED-CHARGE 
FOLLOW-THROUGH BOMB« 

The antisubmarine, shaped-charge, folloAV-through 
bomb was designed to overcome the limitation in 
effective range inherent in a hollow-charge Aveapon 

®This section is constructed from a report prepared by C. 
O. Davis.ibi2 


54 


APPLICATIONS OF HIGH EXPLOSIVES 


dependent on jet action alone for target damage. Work 
on the ASCFT bomb was initiated by NDHC, Division 
8, when it became evident tliat the antisubmarine, 
sbaped-cbarge bomb without a follow-through projec- 
tile (described in Section 3.2) would be ineft'ective 
in a large proportion of hits on the decking and super- 
structure of a submarine, where a total penetration 
greater than the 50 to 60 in. obtainable with the ASC 
l)omb would be required to reach from the plating or 
decking where the bomb makes contact and explodes 
through the intervening oil and water to the pressure 
hull and through the pressure hull. Besides being 
short in penetration, the ASC bomb would make only 
a small hole (1- to iy 2 -in. diameter) in the pressure 
hull. A shaped-charge bomb with a follow-through 
projectile, however, would defeat a submarine by put- 
ting a hole through the decking or saddle-tank shell 
tlirough which a high-explosive projectile, carried in 
the after end of the bomb, would pass. The projectile 
Mould be provided Muth a fuze of long delay to allow 
it to settle against the pressure hull before detonating. 
A large hole in the pressure hull M'onld be expected 
from a fairly small high-explosive charge surrounded 
by M^ater and in contact Muth the hull at time of 
detonation. 

At the time the ASCFT research M'as started, M^ork 
on holloM^-charge devices Avith follow-through pro- 
jectiles had progressed far enough both here and in 


(Ireat Britain so that some features of the assembly, 
sucli as design and sliape of rear of forward charge 
to minimize blast effect on the folloM^-through projec- 
tile, Mere already established. The chief problems to 
be solved, and their solutions, folloM^ The M'eapon itself 
is slioMui in Figure 2. 

^ Size and Type of Forward Charge 

The most resistant target wdiich the foi'M^ard charge 
M^as expected to defeat M^as a V 2 -in. saddle-tank shell 
M ith M'hich the bomb nose M'onld be in contact at the 
instant of detonation. The smallest charge Mdiich 
M^ould dependably open a large hole in a V 2 -in. plate 
Mas 3 lb of Torpex, 3 in. in diameter, having a 45° 
cone and lV 2 -in. base diameter, inserted into the 
rounded nose of the charge. The results obtained Muth 
this foiMvard charge indicated that the jet from the 
cone perforated the y 2 -in. plate, after Mdiich the plate 
M'as bloMui open by blast. The charge without a cone 
M^ould not hole the plate. Furthermore, Mdien the cone 
M'as the full diameter of charge there Avas no blast 
damage and the hole Avas too small for the folloAV- 
through projectile. 

3.3.2 Design of Follow-through Projectile 

A projectile of square cross section Avas designed 
because such a projectile in contact Avdth an air-backed 
1-in. plate representing the pressure hull, easily de- 




SECTION A-A 

Figure 2. Antisubmarine shaped-charge folloM^-through bomb. 


kwixrihK.vnA U 


SHAPED-CHARGE WARHEADS FOR NAVAL TORPEDOES 


55 


feated the plate when the high-explosive load in the 
projeetile was only 5 oz. of Composition 1> or the 
equivalent, whereas a projeetile of conventional cir- 
cular cross section required about 1.5 lb of filler 
to defeat the target. The preferred projectile of square 
cross section was iy 2 in. wide and 5% in. long. 

3.3.3 Propulsion of FT Projectile 

The terminal velocity of the ASCFT bomb in water 
was expected to be only 20 to 30 fps, or too Ioav to 
cause the follow-through projectile to follow through 
the foi’Avard blast bubble and into the target. A mor- 
tar Avas therefore developed AA’hich fired the projectile 
at the required velocity of approximately 500 fps. The 
afterend of the projectile carried a special removable 
gas check, so that the square projectile could be fired 
from a gun of conventional circular bore. Smokeless 
poAvder Avas used as propellant. 

3.3.4 Timing of Explosive Elements 

Proper functioning of the various parts of the bomb 
required the folloAving sequence of actions. 

1. Nose of foi’Avard charge makes contact Avith 
target. 

2. Propellent charge is ignited in FT mortar. 

3. FT projectile accelerates to full A’elocity and 
emerges fully from mortar. 

4. ForAvard charge ex})lodes in contact Avith target. 

5. FT projectile passes through the gas bubble and 
target, comes to rest, and eventually detonates. 

An external fuze Avas not developed, although a de- 
sign Avas proposed by the xVnimunition Development 
Division, Ordnance Department, Avhich Avould employ 
a Belleville spring. It Avas assumed, however, that an 
external nose fuze A\muld ignite the primer in the FT 
mortar, perhaps through a Primacord strand, and that 
the projectile itself Avould detonate the forward charge 
by striking an element of a fuze installed at the after- 
end of the forAvard charge. All experimental bombs 
Avere arranged for firing in this manner. In order to 
avoid movement of the bomb during the acceleration 
of the projectile the FT mortar recoiled alone by slid- 
ing freely Avithin the bomb body. 

FT Projectile 

A high-explosive projectile Avas designed which was 
not disrupted or deflected by detonation of the forward 
charge or by passing through the resulting high-pres- 


sure gas bubble. A suitable 5-second delay unit Avas 
designed at Picatinny Arsenal Avhich, Avith some 
modilications, functioned properly. 

Successful static tests Av^ere run Avith bombs Avhich 
Avere complete except for external fuze, tail, and safe- 
ty devices. These tests demonstrated the Avorkability 
of the ASCFT bomb. The using Service Avith a re- 
quirement for such a Aveapon Avill be able to start Avith 
the design deA^eloped under this project but Avill have 
to furnish suitable fuzes Avith safety devices, complete 
the external design of the bomb including fuze and 
tail, and deAelop bundles and clusters of the bombs. 

Designs for larger editions of the ASCFT bomb 
could probably be derived by scaling up the model 
deA’eloped under this project. 

34 SHAPED-CHARGE WARHEADS FOR 
NAVAL TORPEDOES" 

Shaping the charge in the Avarhead of a naval 
torpedo to cause deep penetration into a struck ship 
Avas among the earliest proposals for military applica- 
tion of shaped charges. A project to develop shaped- 
charge AA'arheads for Mark 13 (aircraft), Mark 16 
(submarine), and Mark 17 (destroyer) torpedoes was 
authorized late in 1942 by the Bureau of Ordnance 
primarily Avith expectation of greatly enhanced incen- 
diary action from such Avarheads. Early tests Avith 
experimental cone-lined charges 6 in. in diameter 
(hetAA^een 1/3 and 1/4 scale) showed that the jet from 
such charges Avould set fire to combustibles like smoke- 
less poAvder and oily Avaste, after penetrating a series 
of steel plates separated by Avater, corresponding to 
the compartmented torpedo defense systems used in 
American aircraft carriers and various other Avarships. 
Subsequent Avork dealt chiefly Avith the problem of 
converting the existing Avarheads to holloAv-charge 
heads of greatest possible depth of penetration, with- 
out changing the external shape of the Avarhead, or 
the total Aveight, center of gravity, and ^^pull-around” 
of the torpedo. 

As Avas true Avith nearly all existing munitions con- 
verted from conventional high-explosive to hollow- 
charge types, the best Avay to modify a warhead to 
give deep penetration was to install a small angle 
(about 45°) steel or copper cone of as large diameter 
as possible in the forAvard end of the warhead, with 
the long axis of the cone coincident with that of the 
Avarhead. 

‘^This section is taken from a summary prepared by C. O. 
Davis. 


EOyErDKNTlAJ^ 


56 


APPLICATIONS OF HIGH EXPLOSIVES 


Several diU'erent eompartmeiited targets, dift'eriiig 
in tlie tliiekness and spacing of the steel bulkheads 
and in the location of the air-filled and water-filled 
conipartinents, were proposed hy the Bureau of Ord- 
nance and the Bureau of Ships in the course of the 
work and used in full-scale and scaled-down static 
testiiig. The two full-scale targets in use hy the Navy 
in tests at Solomon’s Island near the end of the proj- 
ect were as follows. 

1. Midway Defense System (Full-Scale) 

Bulkhead Skin 1 2 3 4 Safety 

Thickness j in. ^ in. § in. Ij in. ^ in. 

Spacing 5 ft 4 ft 4 ft 4 ft 7 ft 

Interplate Water Water Air Air Air 
loading 

2. Japanese Defense System (0.304-Scale) 


Bulkhead 

Skin 1 

2 

3 

4 

Safety 

Thickness 

1 in. 

in. ^6 

in. f in. 

1 in. 


Spacing 

ISi in. 

141 in. 

141 in. 

141 in. 

G ft 

Loading 

Air 

Water 

Water 

Air 

Air 


These defense systems and others were defeated hy 
a modified Mark 13 warhead of the same scale, attack- 
ing at 30° from normal, hut the other warheads con- 
sidered for modification were either too short or had 
such gradually tapered noses that a sufficiently large 
cone to defeat these defense systems could not he in- 
stalled in them. Consequently only the hollow-charge 
^lark 13 or aircraft torpedo warhead was successful, 
and work on the others was dropped. 

Much of the testing to arrive at size and shape of 
hollow metal lining characteristics, and method of 
mounting, nose design, charge shape, initiation, ex- 
plosive composition, etc., was done with charges and 
targets scaled down to various small scales (%o? 

%, etc.) Direct linear scaling was found pemiissihle 
except for the comparison of certain explosives. Alu- 
minized explosives, such as Torpex II, were inferior 
to similar explosives without aluminum in small-scale 
tests hut equivalent or superior at larger scale. This 
phenomenon was observed independently on other 
projects and by other investigators and was considered 
due to the failure of the aluminum to react quickly 
enough to contribute to the detonation pressure in 
charges below a certain (not definitely established) 
size. 

Aluminized explosives were very much superior to 


iionaluminized for underwater blast elfects (pressure 
and impulse and target damage), ajid it was there- 
fore desirable, after adoption hy the Navy of Torpex 
and IIBX for Service warheads, to use aluminized fill- 
ings in the hollow-charge modification of the Mark 13 
warhead. Because of the variation in effectiveness with 
diameter shoAvn hy hollow-charge warheads filled with 
Torpex and other aluminized explosives, complicated 
further hy large variations in the effectiveness of some 
of the handmade steel cones used in the test warheads, 
many series of tests were required before Torpex and 
a modified HBX (see Section 1.12) were adopted as 
fillers for the hollow-charge Mark 13 warhead. 

The hollow-charge modification of the Mark 13 
warhead contained only 520 lb Torpex II, compared 
with 585 lb for the standard Mark 13, and the gen- 
eral blast damage done to the bulkheads near the out- 
side of the ship would probably be greater with the 
standard warhead. Sufficient full-scale tests were not 
made to settle this question. The advantages of the 
hollow-charge warhead would be in defeating, by per- 
forating and loosening and tearing, the bulkheads be- 
yond the sphere of damage of the standard warhead, 
in damage to equipment inside the ship, and in supe- 
rior incendiary effect. 

As with other liollow-charge devices, the prop- 
erties and location of the cone were extremely critical. 
The Mark 13 warhead required a very large cone 
(19V2-in. base diameter, V 2 -in. to %-in. wall, 45° apex, 
100 lb -\- weight), which was difficult to fabricate. 
Satisfactory cones were made by the Pittsburgh and 
Des Moines Steel Company from steel plate of the 
thickness of the cone wall. Each cone was built from 
three identical segments, which were cut to pattern 
and bent to shape. The three seams were welded, the 
cone heat treated (normalized at 1G50 F), and finally 
trimmed inside and out on a lathe to eliminate eccen- 
tricity and variations in thickness or curvature. 

Successful full-scale static tests had been made by 
the Bureau of Ordnance, and a start had been made 
on designing a hollow-charge Mark 13 warhead for 
Service use when hostilities ended. An exploder of es- 
sentially instantaneous action was required before any 
firing tests could be made with a Mark 13 torpedo 
carrying a hollow-charge warhead. Other design work 
remaining, some of which will require firing tests, was 
to provide adequate pull-around and strength in the 
forward end, including the cone mounting to with- 
stand water impact. The firing tests may bring out 
other structural problems. 


(CU]!OnDENTIAli 


SHAFED-CHARGE FOLLOW-THROUGH ROCKET 


57 




ASSEMBLY JOINT 


BOLTS, 6 EQUALITY 
SPACED ON Sy 
DIA CIRCLE 


Figure 3. Shaped-charge torpedo warhead. 


35 SHAPED-CHARGE FOLLOW-THROUGH 
ROCKET’'^ 

The limitation on a yliajied-charge weapon already 
mentioned in earlier sections of this chapter, that it is 
capable of doing hut little mechanical damage after 
penetrating the target, led to the request that a 
shaped-charge projectile with a folloAV-through device 
he developed, ddie final phase of the program had the 
specific objective of developing a shaped-charge follow- 
through rocket which would defeat 4 inches of armor 
plate. The weapon designed to accomplish this was 3V2 
in. in diameter, weighed 10 Ih, and had a velocity of 
300 fps utilizing the 4’-50 rocket motor. The follow- 
through was an ex])losive-loaded missile about the size 
of a 20-mni shell. In the final tests against 4-in. homo- 
geneous armor at normal incidence at 100 yd range, 
the follow-through passed through the target 12 times 
ill 12 shots and detonated after passage in 10 shots. 
Ill comparable trials at 30° incidence, the follow- 
through passed through the target 10 times in 13 shots 
and detonated after passage in 7 shots. The brief dis- 
cussion which follows is limited to a consideration of 


some of the exjilosive problems connected with the 
wea])on. F^or a discussion of pro])ulsion and ballistic 
features, reference must be made to the Summary 
Technical Report of NDRC, Division 3, as these fea- 
tures were the responsibility of the Allegany llallistics 
Laboratory of Division 3. 

In the early work, attempts were made to have the 
follow-through attached to the ajiex of the liner of the 
shaped charge. These attempts were not successful. 
The slug from the liner parted from the folloAV- 
thiough before the latter had acquired any appreciable 
velocity. Another proldem in the early Avork Avas 
Avhether the folloAA'-through AA^ould be appreciably de- 
celerated by the rearAvard blast fium the shaped charge 
and in ])a.ssing through the blast of the shaped charge. 
It Avill be recalled that these effects, coupled Avith the 
loAv terminal velocity of the folloAV-through in the 
antisubmarine shaped-charge folloAV-through bomb 
described in Section 3.4, made it necessary to provide 
separate propulsion for the folloAV- through in that 
Aveapon. Specific tests, hoAvever, made it quite clear 
that in air the loss in speed of the follow-through Avas 
negligible; Avith 80° conical ends on both the charge 


tokeiDiA jiAi.A 



58 


APPLICATIONS OF HIGH EXPLOSIVES 


•and the follow-tlirougli, the loss in speed was not 
greater than 10 fps. 

The principal difficulty encountered in the project 
was the fuzing. In order to secure detonation of the 
shaped charge at the rear and on its axis when the shell 
was at the proper stand-off, a long rodlike striker pin 
parallel to the axis of the charge was used. This pin 
struck a detonator back of the charge and initiated 
the detonation of the charge itself by a connecting 
piece of Primacord. Later the single striker rod was 
replaced by three rods located 120° apart. The use of 
a point detonating fuze was also tried. This fuze, a 
small shaped charge in the nose of the shell which 
fires through a flash tube in the main shaped charge 
by a detonation at its base, was erratic in its action 
and was eventually abandoned in favor of the rod fuze. 
The follow-through has a base fuze with a 5-second 
delay. Although the fuzes functioned satisfactorily 
in the final tests described in Section 3.5, it is felt 
that fuzing is the weakest part of the round at present, 
and further work in the fuzing is recommended before 
the round is considered for adoption. 

36 MISCELLANEOUS APPLICATIONS OF 
SHAPED CHARGES 

^ Destruction of Microwave Tubes 

It is desirable to have some means of destroying 
beyond reconstruction planeborne radar equipment 
should the plane be forced to land on enemy territory. 
This can be done by a shaped charge with a liner of 
sand bonded by a thermosetting resin. The jet from 
this charge does not have the penetrating power of 
that from a steel liner, but it does a much better job 
for this special application. An 80-g shaped charge of 
either Composition B or 50/50 Pentolite, placed about 
3 in. from the target and lined as just described, de- 
stroyed the radar oscillator as specified with only small 
danger to the plane’s personnel from blast or frag- 
ments; however, the damage to the plane’s fuse- 
lage was too great to permit use of the device in 
flight.i^-i® 

^ ^ ^ Shaped-Charge Boosters 

A shaped charge is the source of a jet of high in- 
tensity, and it is quite natural that the suggestion of 
using this jet in boosters would arise. The particular 
problem preseijted to Division 8 was the use of a 


shai)ed-charge booster for the 5-in./38 A A projectile 
loaded with Explosive D. Tests showed that the stand- 
ard flat-ended booster was perfectly adequate in this 
shell, so that nothing was to be gained by going to a 
shaped charge. The only situation envisaged when the 
use of a shaped-charge booster would be advantageous 
would be that where, because of peculiarities of design, 
the booster was some distance from the main charge.”” 

37 BEANO® 

In August 1943, the Office of Strategic Services re- 
quested Division 19 of NDIIC to develop a special 
hand grenade. This grenade, which was given the 
code name Beano, was to be thrown like a baseball and 
was, if possible, to be of the same size and weight as 
a baseball. Preliminary throAving tests, made at the 
Maryland Pesearch Laboratory of Division 19 Avith 
AA^ooden spheres of varying Aveight but of approxi- 
mately the same size as a baseball, shoAv^ed that the 
Aveight of these spheres could be increased to 12 ounces 
Avithout greatly affecting either accuracy or distance. 
The folloAving specifications Avere then set for the 
grenade : 

1. It should be spherical and approximately 2% in. 
in diameter. 

2. It should AA^eigh 11 dz 1 ounces. 

3. It should be spherically balanced and should not 
exhibit eccentricity in flight. 

4. It should fire as a result of a free fall of 18 in. 
onto a sponge rubber surface. 

5. It should have optimum lethal fi'agmentation. 

G. It should have tAvo arming mechanisms, the in- 
itial arming to be reversible and the final arming to 
take place during flight. 

Division 19 took the responsibility for AA^ork on the 
fuze, Avhile Division 8 took responsibility for all prob- 
lems involving the high-explosive charge. This in- 
cluded not only the selection of the charge, but also 
the testing for fragment effectiveness and for sensi- 
tivity to rifle fire and sympathetic detonation.* * A con- 
tract Avith the Eastman Kodak Company provided for 
developing the completed Aveapon with the assistance 
of Divisions 8 and 19 and engineering it for possible 
quantity production. 

®This section is based on information supplied by L. H. 
Farinholt. 

*The work of Division 8 on Beano has not been described 
in an OSRD report. This work is to be found, however, in 
Reference 21 and in Summary Technical Report Division 19, 
Volume 1, Chapter 4. 


EXPLOSIVE STREAMERS 


59 


Since 12 ounces was the inaximiim weight allowed 
and since it was estimated tliat the fuze assembly 
would weigh about 2 ounces, there was left 10 ounces 
for the case and the explosive charge. With both the 
Weight and the dimensions fixed, it was thought that 
a magnesium or aluminum case might be more effec- 
tive than a steel case because of the greater wall thick- 
ness for a given weight permitted by the light metals. 
Fragmentation tests, however, showed that a thin- 
walled steel case was more effective than thick-walled 
aluminum or magnesium cases of equal weight. Addi- 
tional fragmentation experiments showed that, for a 
total weight of explosive and casing fixed at 9 to 10 
oz, an 0.040-in. wall steel case was more effective than 
an 0.060-in. wall steel case of the same diameter. On 
the basis of these and other fragmentation experiments 
it was decided to use a spherical steel case, 0.040 in. 
thick and 2%-in. OD, welded at the equator and filled 
with explosive having a density of about 0.9. With 
this arrangement the explosive charge and the case 
each weighed approximately 4.5 ounces. 

Some fragmentation tests were made with charges 
of cast explosives, but, because of the high density of 
the castings,® the permissible amounts of explosive 
occupied so little space that they created loading prob- 
lems. xAttention was then turned to the following ex- 
plosives at hand-packing densities : TNT, ammonium 
picrate. Composition A, and waxed TNT. Granular 
TNT is probal)ly best from the standpoints of avail- 
ability and simplicity, but it is somewhat sensitive to 
.30-caliber rifle fire. Composition A is safe to .30-cal- 
iber rifle fire. Grenades loaded with any one of the 
four named explosives will detonate sympathetically 
when the grenades are in direct contact with each 
other. Sympathetic detonation can be prevented, how- 
ever, by separating the grenades in the container 
with a layer of cardboard of moderate thickness. 

Composition A, granular TNT, and waxed TNT all 
gave satisfactory fragmentation, while ammonium 
picrate was decidedly inferior. At a range of 3 ft, a 
grenade filled with Composition A at a density of 
approximately 0.9 gave twice as many fragments pene- 
trating a 1-in. pine board as did a similar grenade 
loaded with granular TNT at a density of 0.8. How- 
ever, the holes in the board from the Composition A 
filled case had only half the average area of those 
from the TNT filled case, so the total area punched 
out was about the same for the two fillings. The 
fragments from the Composition A filled case Avhich 

«Cast 50/50 Pentolite, for example, has a density of from 
1.59 to 1.65. 


went through the pine board had an average 
linear dimension of about 0.23 in. ; the comparable 
fragments from the TNT filled case had an average 
linear dimension of about 0.31 in. The average veloc- 
ity of the fragments from a Composition A filled gre- 
nade is considerably greater than from the other 
fillings. 

The relative effectiveness at 3 ft and at 10 ft has 
been determined for TNT loaded and Composition A 
loaded Beanos. With the TNT charge the number of 
fragments perforating 1-in. pine board decreases 38% 
when the target distance is increased from the shorter 
to the longer distance. With the Composition A charge 
the corresponding decrease is 50%. However, the 
number of fragments which go through the pine board 
is greater at both distances with the Composition A 
filling. 

Comparisons have been made of the fragment effec- 
tiveness of the Beano grenade and the standard Mark 
2 fragmentation grenade, whose total weight is about 
twice that of the Beano. At a range of 3 ft, the Mark 
2 grenade filled with 2 oz of TNT is about equivalent 
to a TNT filled Beano but distinctly inferior to a 
Composition A loaded Beano. The Mark 2 grenade, 
loaded either with EC powder or granular or flaked 
TNT, gives no fragments from the quadrant center- 
ing around the fuzed end which will penetrate 1-in. 
pine board at a range of 3 ft. With the Beano gren- 
ades the middle third of the quadrant centering 
around the fuzed end gives a high concentration of 
effective fi‘agments. 

38 EXPLOSIVE STREAMERS*' 

In the fall of 1942, Division 8 was requested by the 
Navy to assist the Naval Ordnance Laboratory with 
the development of the explosive features of the Holm 
Antitorpedo Device, later designated the Mark 29 
Mine. This device consists of two sets of three stream- 
ers, each 400 ft long, which are towed parallel to and 
at some distance from the two sides of a ship by means 
of paravanes. The streamers, which must have a slight 
positive buoyancy, are towed at 10 to 30 ft below the 
surface. The streamer farthest from the ship on each 
side contains detecting equipment which signals the 
approach of a torpedo through the water. The two 
inner streamers carry an explosive charge, about 1.5 
to 2 11) per foot. When a torpedo passes under the de- 
tector streamer, the outer explosive streamer is de- 

**This section is constructed from reports furnished by D. 
P. MacDougall and C. O. Davis.22-24 




60 


APPLICATIONS OF HIGH EXPLOSIVES 


tonated after a slight delay, so that the torpedo is 
destroyed or at least prevented from reaehing the 
ship. Shonld a second torpedo later a])proaeh the ship 
from tlie same side, it is dealt with in a similar way l)y 
the other explosive streamer. 

The first form of explosive streamer, or hose, devel- 
o])ed hy the Naval Ordnance Laboratory consisted of 
a large rubber hose partly filled hy cans, 2 in. in diam- 
eter and 8 in. long, of Nitramon-S primer, an amatol- 
like ex]dosive. Primacord was used to insure propa- 
gation from call to can. This hose had a number of dis- 
advantages, the chief ones being that it was very time- 
consnming to load and that detonation of one of the 
explosive hoses compressed the explosive in the adja- 
cent hose sufficiently to prevent it from propagating 
detonation when called upon to do so. 

A suitable design of explosive streamer had to meet 
a nnmher of conditions : ease of manufacture in large 
quantities; flexibility (the filled hose had to be able 
to be wound on a 3-ft reel) ; ability to stand counter- 
mining and rough handling; reliability of propaga- 
tion ; and suitable buoyancy. 

Two organizations were chosen to work on the 
NDHC phases of this development, the Eastern Labo- 
ratory of the du Pont Company and the Explosives 
Pesearch Laboratory at Bruceton. Each group con- 
sidered both discrete charges and continuous, long 
charges for the filling, but the major developments 
made by both groups, although somewhat different, 
involved rather long, flexible inner hoses filled with 
explosive. The development at the Explosives Pesearch 
Laboratory will be described first, and will be followed 
by a description of the developments at the du Pont 
Eastern Laboratory. 

At the time work was begun, the only explosives 
available in sufficient quantity were TNT and, pos- 
sibly, Pentolite. Because of the requirement that the 
streamer have slight positive buoyancy, and because 
the densities of all the hose materials and metal coup- 
lings are considerably over one, it seemed impossible 
to avoid using the Naval Ordnance Laboratory scheme 
of providing buoyancy by using for the outer container 
a hose partly filled with explosive and partly filled 
with air under pressure. No practical way was found 
for filling the outer hose completely with explosive 
material having a density considerably less than one. 
An inner hose filled with cast TNT would have been 
simple to produce, but it would not have met the flex- 
ibility requirement nor would it have propagated re- 
liably. Cast Pentolite would have propagated satis- 


factorily but it would not have been flexible and it 
might have been too sensitive. 

it was discovered at the Explosives Pesearch Labo- 
ratory that, if a hose is filled with molten TNT and 
then flexed gently during the cooling period, the re- 
sulting charge consists of finely divided TNT at a 
density of about 1.40 g per cc. Because the TNT is 
powdered, the filled hose is fairly flexil)le, meeting the 
requirement easily, and the charge propagates reli- 
ably. (Pressed crystalline TNT propagates detona- 
tion reliably under conditions of diameter and con- 
finement for which cast TNT will usually fail to 
propagate. ) 

d'he first mechanical device for carrying out this 
flexing operation was built and operated at Bruceton, 
but for larger scale studies a group from the Explo- 
sives Pesearch Laboratory went to the Naval Mine 
Depot, Yorktown, Virginia. The first flexing machine 
involved reciprocating arms and gave the filled hose 
a rather snake-like motion while cooling; later it was 
found that a more gentle treatment would be ade- 
quate, and the final flexing machine consisted of a 
pair of large drums, -1 ft in diameter with 1-ft face, 
spaced 7 ft apart and connected by a continuous belt. 
Twenty-five-foot lengths of hose, filled with molten 
TNT and plugged, were wi’apped around the two 
drums and the ends fastened, dfiie machine was run 
for about 50 minutes, after which the hose was found 
to be almost completely filled with fine-grained TNT, 
with only an inch or less of hard material at the ends. 
Several sizes and varieties of hose were successfully 
loaded and flexed, but for the specified load of 1.5 lb 
])er foot, hose with 1.75-in. ID, was suitable. Some 
2,400 ft of hose were loaded and flexed with the two- 
pulley machine described above. The capacity of this 
machine was four 25-ft lengths per hour. By increas- 
ing the width of the pulley faces to 3 or 4 ft, the out- 
put could he stepped up considerably with little in- 
crease in space requirements. 

In addition to developing the flexed TNT-filled 
inner liose, suitable outer hose and couplings were 
designed and procured. The completely assembled 
streamers were tested for propagation and counter- 
mining. The propagation tests were completely suc- 
cessful in 400-ft lengths, but the streamers stood up 
only moderately well to the detonation of a similar 
streamer near hy. This was a fault of the outer hose 
and conld have been remedied. However, due to chang- 
ing requirements, this type of streamer was never ac- 
tually used in service in the Mark 22 Mine. Interest 


EXPLOSIVE STREAMERS 


61 


was aroused in the possibilities of using the inner hose 
as a demolition charge. A somewhat larger hose was 
used in order to increase the weight of explosive per 
foot, and it was given the designation of the Mark 8 
demolition charge. On the basis of the work carried 
out for the ^lark 29 hose, Explosives Eesearch Labo- 
ratory personnel cooperated with Navy personnel in 
the design of a plant for producing this flexible ex- 
plosive hose. A plant was built at Yorktown to this 
design, and was operated for some time at a rate 
understood to have produced about a million pounds 
a month of explosive hose. 

The Eastern Laboratory of the du Pont Company 
developed a 50/50 mixture of grained and flaked TNT 
which could be poured into the canvas inner tube to 
the same loading density as was attained with grained 
TNT by vigorous hand tamping. This simplified and 
speeded up the loading. The improved TNT canvas- 
sock load was used in all of the Service tests and ac- 
tual applications of the Mark 29 device, although the 
explosive streamers containing this load were objec- 
tionable for the following reasons. 

1. Primacord was needed to insure propagation. 
The Primacord was bullet sensitive, easily desensi- 
tized by water, and tended to cut off during detonation 
at places where it was looped or bent. 

2. Loose TNT was not particularly waterproof, fire- 
or bulletproof. 

3. The streamer had an undesirably large amount 
of metal in it as couplings between 25-ft lengths. This 
made more difficult the attainment of buoyancy and 
cut down on flexibility. A single continuous column 
of explosive appeared desirable in place of 25-ft 
lengths. 

4. The use of compressed air for buoyancy required 
special extra-heavy hose to contain the explosive and 
air and introduced various complications in the han- 
dling and storage of the streamers. Pubber was very 
scarce, and large quantities were required. 

A load consisting of pressed, round-ended pellets 
of TNT, strung like beads on Primacord, was first 
proposed to replace sock loading. The pellets could be 
pressed at an Army Ordnance Works and shipped to 
the Mark 29 assembly plant where assembly into the 
buoyancy hoses would be very easy and rapid. This type 
of load was unsuccessful, however, in countermining 
tests. The pellets developed dust, and some breakage 
occurred. 

A series of slurry-type explosives was developed 
which could be poured or pumped into continuous 
tubes of various sizes down to 1 in. in diameter. The 


two preferred compositions and their properties are 
given below. 



Comj)osition Composition 


EL-387A 

EL-387B 

50/50 Pentolite 

30.0% 

24.0% 

Ammonium nitrate 

54.0% 

43.2% 

Water 

13.5% 

10.8% 

Starch 

2.5% 

2.0% 

Aluminum (MDlOl) 

None 

20.0% 

Density of filling 

1.33-1.40 

1.50 

Triton value 

10.0 

13.4 

TNT equivalent, from 


underwater blast 
measurements 

0.856-lb TNT/lb 

1.207-lb TNT/lb 

Propagation 

Sensitiveness 

OK in 1 in.x50 ft 

OK in 1 in.x50 ft 

Air gap 

12 in, in If in. diam 11 in. in If-in. diam 


2 in. in 1-in. diam 

0 in. in 1-in. diam 

Water gap 

4 in. in If-in. diam 

4 in. in l|-in. diam 


I-in. in 1-in. diam 

0 in. in 1-in. diam 

Cap sensitivity 



Eng. Spec. No. 8 

Detonated 

Detonated 

No. 6 EBC 


Failed 

Thermal stability 

Brown fumes at 

Brown fumes at 


150C* 

150C* 


Ignited at 

Ignited at 


170tol80C* 

170tol80C* 

*Same as 50/50 Pentolite. 




Pentolite was used as the sensitizer for the explo- 
sive slurry because it detonates dependably in water. 
Ammonium nitrate was used as a source of strength 
and also because its solubility in water increases very 
rapidly as the temperature is raised. Both EL-387 A 
and P> were mixed and poured at 60 to 70 C, or just 
below the melting point of the Pentolite. On cooling 
to room temperatui-e both slurries stiffened due to 
crystallization of ammonium nitrate. The resulting 
column of explosive was flexible down to — 30 C, but 
sufficiently solid so that settling of solid ingredients 
did not occur. Seepage of liquid was avoided at room 
temperature and above by addition of a small amount 
of starch. 

The water-slurry compositions were satisfactory 
as regards propagation, strength, stability, and failure 
to be exploded by rifle bullets. Hoses loaded with 
them withstood rough handling tests by Naval Ord- 
nance Laboratory and were flexible and easily mani- 
pulated. 

Some uncertainty existed throughout the Mark 29 
project concerning the weight of explosives to use per 
foot of streamer. It was desirable to keep the weight 
at the minimum which would destroy torpedos at a 
reasonable maximum distance of 20 ft. Larger charges 
than the bare minimum had to be avoided to keep 
at a minimum the damage done by the exploding 
streamer to the ship it was protecting, and the damage 


^yFir)F.XTm4 


62 


APPLICATIONS OF HIGH EXPLOSIVES 


to the audio-detector streamer. The TNT sock load 
was 1.6 lb per foot, and the experimental streamers 
Were loaded to a TNT equivalent (based on Triton 
value) of 1.6 lb per foot. Tests by the Naval Ord- 
nance Laboratory toward the end of the project in- 
dicated that a charge Aveigbt of 1.0 to 1.2 lb of TNT 
per foot might be adequate. 

Explosive streamers loaded with EL-387 A and B 
were unsatisfactory oidy with respect to overall 
density, wbicli was 1.35-1.50 g per cc. The overall 
density of a Mark 29 streamer bad to ])e approxi- 
mately 1.04 g per cc for proper buoyancy. Unsuccess- 
ful attempts were made to obtain this buoyancy by 
bringing the slurry density down by the addition of 
buoyant diluents and by the use of various floats 
within or around the streamer. Finely divided mate- 
rial within the explosive interfered with propagation 
and strength, and large pieces of buoyant material 
failed to withstand countermining. It was necessary 
to retain tlie Naval Ordnance Laboratory method of 
regulating buoyancy with compressed air. 

The production of Mark 29 units by the Navy was 
discountinued before any streamers developed by 
NUBC had received complete field tests. 

Nonbuoyant streamers loaded with EL-387A or B 
would be useful line-demolition charges, particularly 
for underwater demolitions. EL-387A and B would 
he particularly well suited for use as ^hlrone’^ charges, 
where it is desired to load or pour the maximum 
weight of explosive in minimum time in a boat or 
similar carrier of any size or shape which is to be 
run up to the firing point by remote control and de- 
tonated en masse. 

3.9 LIQUID EXPLOSIVES' 

At the request of the Army Corps of Engineers, 
under Service Project CE-32, Division 8 was asked 
to develop a liquid explosive for use in mine clearing. 
The Division was also requested to furnish help and 
advice on the design and construction of a device for 
dispensing a liquid explosive in the field into a flex- 
ible hose. The hose itself was to be laid in the mine 
field by means of a rocket and upon detonation was 
expected to clear a safe path for tanks and for per- 
sonnel. It was the responsibility of Division 8 to de- 
velop the explosive, and it was the responsibility of 
the Corps of Engineers to evaluate its mine-clearing 
efficiency. Besults on standard minefields are reported 

'This section is taken from a summary prepared by Howard 
J. Fisher.25,26 


by the Engineer Board, Ft. Bel voir, Virginia, and 
will not be discussed here. 

The requirements for the liquid explosive were as 
follows : 

1. It should be safe to handle both during manu- 
facture and transport. 

2. It should be as insensitive as possible to enemy 
small arms fire. 

3. It should propagate a high-order detonation in 
diameters as low as 1 in. in the unconfined state. 
This requirement was later altered to permit propa- 
gation in diameters only as low as 3 in. because a 
larger hose carrying a minimum of 4.5 lb of explo- 
sive per foot was expected to be used against anti- 
tank mines. 

4. It should be capable of being stored in the usual 
Service magazines. 

5. It should have a low freezing point to avoid 
crystallization in the field. 

The development of liquid explosives was carried 
out at the Explosives Eesearch Laboratory, Bruceton, 
Pennsylvania, under Contract OEMsr-202 and at the 
Eastern Laboratory of the du Pont Company, Gibbs- 
town. New Jersey, under Contract OEMsr-828. Tests 
were conducted at the Engineer Board Field Station, 
Port Boyal, Virginia. 

Four liquid explosives were developed. All were 
based on a 75/25 nitroglycerin-nitroglycol mixture 
(No. 8 oil) because it is the only liquid explosive 
manufactured in this country in sufficient quantities 
for wartime use. The nitroglycol was used to lower 
the freezing ])oint of the nitroglycerin. 

Two compositions based on nitroglycerin desen- 
sitized with dimethyl phthalate and stabilized with 
ethyl centralite were developed at EEL. Two other 
compositions based on nitroglycerin desensitized with 
a 70/30 mixture of DNT oil-TNT and stabilized with 
diphenylamine were developed by the du Pont Com- 
pany. The exact formulations follow. 


Methylite 20 


Methylite 25 


Nitroglycerin-nitroglycol 


Nitroglycerin-nitrqglycol 


(75/25) 

80 

(75/25) ^ 

75 

Dimethyl phthalate 

20 

Dimethyl phthalate 

25 

Ethyl centralite 

0.8 

Ethyl centralite ' 

0.75 

EL-389 A 


EL-389 B 


Nitroglycerin-nitroglycol 


N i trogly ceri n-ni trogly col 


(75/25) 

55 

(75/25) 

60 

DNT oil-TNT (70/30) 

45 

DNT oil-TNT (70/30) 

40 

Diphenylamine 

0.55 

Diphenylamine 

0.6 


Considerable time was devoted to a study of the 
sensitivity of these liquids in a number of impact 
machines. Depending upon the conditions of confine- 


[TTTxkiiikn'ti \n 


LIQUID EXPLOSIVES 


63 


ment and upon the types of strikers and anvils used, 
the sensitivity of all the liquids ranged between that 
of dry PETN and crystalline TNT. In all cases they 
were shown to be considerably less sensitive than 
nitroglycerin. Furthermore, they were found to be 
insensitive to frictional impact and did not detonate 
in any friction device tried. 

Methylite 20 and 25 and EL-389B and A were also 
found to he insensitive to .30- and .50-caliber hall and 
tracer ammunition when backed by air and confined 
in 1- and 3-in. diameter neoprene-impregnated Fiher- 
glas hose. They gave fires approximately half the time 
when struck by .30 caliber incendiary ammunition 
and gave detonations when fired upon with .50 caliber 
incendiary ammunition. 

The four liquid explosives studied were, in a limited 
number of tests, insensitixe to .30 caliber ball and 
tracer ammunition Avhen contained in thin steel con- 
tainers (such as Jerricans or Army Air Forces gas- 
oline cans) or when held in light-walled aluminum 
containers which were rubber lined. They are probably 
sensitive to incendiary ammunition in both the lined 
and unlined containers. 

In order to satisfy Navy shipping requirements, a 
number of drop tests were made. In the first series of 
tests these liquids were shown to be insensitive to 
drops of 50 ft onto armor plate supported by packed 
earth when contained in Army Air Forces gasoline 
cans and packed for shipping in boxes of %-m. wood 
having about 1 in. of sawdust between the Avood and 
the container. Ten drops were made with each ex- 
plosive. 

Another series of drop tests was made under the 
following conditions at the request of the Bureau of 
Ordnance. A special shipping container developed by 
the packaging section of Picatinny Arsenal specifi- 
cally for these liquids was dropped from a height of 
50 ft onto armor plate studded with railroad spikes 
arranged so that at each drop at least one spike pene- 
trated the container. 

The Picatinny containers are 10-in. cubes made of 
thin copper covered on the outside with %-in. ply- 
wood held in place by a mortised joint which runs 
along each edge of the cube. The top cubical face 
contains a large hole near the center for filling and 
emptying. The closure for this hole consists of a 
neoprene-gasketed lid held in place by a spider. Two 
of these containers, each holding 2^/2 gallons (30 
lb of explosive) are packed in a box similar to a 
standard ammunition box and having approximate 
dimensions : 26-in. inside length, 14-in. inside width 


and depth. This box is made of %-in. wood with re- 
inforcement at the ends. The two inner cubical con- 
tainers are spaced Avith Celotex and cardboard so that 
they are about 2 in. from each other and from each 
inner face of the ammunition box. 

In ten drops each Avith Methylite 25 and EL-389 A 
there Avere no detonations. In every drop the spikes 
penetrated the containers and liquid Avas spilled onto 
the armor plate. 

Taa^o devices Avere designed for dispensing these 
liquid explosives in the field. They Avere built by the 
M. W. Kellogg Company, Jersey City, NeAV Jersey, 
under an Engineer Board contract. A representative 
of Division 8 from the ExplosiA^es Eesearch Labora- 
tory and from the du Pont Company approved and 
selected vah^es, connections, and closures for the tanks. 
In all cases AAdiere contact Avith the liquid explosiA^e 
Avas expected, the moving parts Avere arranged so that 
no metal-to-metal contact Avas possible betAveen sur- 
faces AAdiich Avere Avet Avith liquid explosive. The first 
prototype, knoAAui as the Dragon No. 1, Avas built to 
hold 2,250 lb of liquid explosiA^e. The tanks were in- 
stalled in a MlOAl 3-in. gun carrier. The liquid was 
forced from the tank through a rubber-lined valve 
into a 500-ft length of 3-in. neoprene-impregnated 
Fiberglas hose Avhich Avas launched by a rocket. It Avas 
possible to dispense the 2,250 lb of explosive in IV2 
minutes under air pressure of 70 psi. 

The second device, knoAvn as the Dragon No. 2, 
Avas arranged for holding 4,500 lb of liquid explosiA^e 
in three tanks connected in series. The containers Avere 
completely enclosed in a T4 25-ton tank. Space Avas 
also left for a driver, an assistant driA^er and an ex- 
plosive operator. In this design the liquid Avas forced 
into three 150-ft hoses 3 in. in diameter launched by a 
rocket-and-yoke mechanism so that the three hoses 
fell in a lane no Avider than 15 ft. This arrangement 
Avas necessary because it Avas shoAAui by tests that a 
single linear charge did not clear an adequate path 
for tanks through the quite insensitiA^e Japanese land 
mines. It Avas expected from static tests with hand- 
laid hoses that three hoses lying symmetrically in a 
15-ft lane AA^ould clear an adequate tank path. 

Boosters AAdiich Avill initiate high-order detonation 
at a velocity of 6,800 to 7,400 mps in these liquids 
may be made of cast Pentolite or Composition C-2 
arranged in a cylinder, 5-in. OD by 3-in. ID by 6 in. 
long, placed around the hose or, more simply, by 
shooting small shaped charges axially or diametri- 
cally into the hose. 

Valve, tank linings, and hose materials may be 


f f^riPF.VITAT^ 


64 


APPLICATIONS OF HIGH EXPLOSIVES 


made of neoprene, componnded GRS, Vinylite, Buta- 
cite, or Koroseal. Neoprene and componnded GRS 
are probably the best. Hycar, noncomponnded GRS 
and Resistoflex are not satisfactory. 

Briefly summarized, the problem stands as follows. 
Four liquid explosives have been developed. These 
are based on commercially available materials, have 
withstood one month’s storage at 71 C (160 F), and 
have been stored for two years at ordinary tempera- 
tures without apparent deterioration. They are in- 
sensitive to .30 and .50 caliber ball and incendiary 
ammnnition Avhen nnconfined. They are not detonated, 
when properly packaged, hy drops of 50 ft onto spike- 
stndded armor plate. Being of reasonably low viscosity 
(about 80 centipoises at 0 C) and of reasonably low 
freezing point (about —10 C), they may he dispensed 
at temperatures usually encountered in the field into 
flexible hoses 3 in. in diameter at the rate of about 
one ton in 90 seconds by air at a pressure of 80 psi. 

3 10 INCREASED VISIBILITY OF 
AA SHELL BURSTS 

An early request made of Division 8 was to devise 
a method of increasing the visibility of the bursts of 


antiaircraft shell. A quantitative photographic meth- 
od was employed to measure the brightness of bursts 
of Vs (weight) scale models of 3-in. A A shell. The 
standard loading of the model shells was 150 g of 
cast TNT plus a 20-g tetryl booster. When 15 g in- 
crements of the following materials were added the 
ratio of the brightness of the burst to that of the 
standard loading was 


Red phosphorus 

15 

Silicon 

50 

Aluminum 

400 


The silicon and aluminum should be placed in a small 
container at the base of the shell in order to be most 
effective. With the aluminum, variations in particle 
size between 20 and 250 mesh were without effect. Alu- 
minum also increases the duration of the flash from 
about 2.5 to about 17 milliseconds. The original re- 
ports show the improvement in visibility attained by 
using less than 15-g increments; this permits the 
calculation of the amount of additive required to 
produce a given visibility. Tests with other additives, 
less effective than the three listed above, are also re- 
ported.^^’^® 


! 


! 


Chapter 4 

EXPERIMENTAL STUDIES OF EXPLOSIVE PHENOMENA 


T his chapter will deal almost entirely with studies 
of shaped eharges,^ hut that discussion is preceded 
by a very brief meutiou of the flash photographic tech- 
nique and its application to explosive phenomena and 
by a summary of studies of shell fragmentation. 

41 FLASH PHOTOGRAPHY 

When a solid sphere of high explosive, for example 
50/50 Pentolite, surrounded by argon, is detonated 
at its center, the resultant shock wave in the argon 
produces a flash of light of high intensity and short 
duration. (Under favorable circumstances durations 
of 0.5 microsecond have been obtained). The inten- 
sity of the flash is roughly proportional to the spher- 
ical surface of the explosive, its duration to the thick- 
ness of the gas layer. ^ The light flash enables explo- 
sive phenomena to be studied photographically. 

Two extensions of the technique have consideral)ly 
enhanced its utility.^ 

The first consists of the use of a high-speed shutter 
which permits reflection photographs to be made of, 
for example, expanding shell cases without interfer- 
ence and fogging from the relatively long duration 
shock wave and combustion luminosity of the detona- 
tion products. When simple shadow pictures are made, 
it is possible to use a small enough camera lens open- 
ing to prevent interference by the relatively low-in- 
tensity after-light. When reflection pictures are made, 
however, the subject light intensity is much lower, 
and in order to prevent the after-light from fogging 
the picture, the camera must be closed in a time of the 
order of microseconds after the detonation of the 
flash bulb. 

A simple and effective shutter was devised by pass- 
ing the ends of two pieces of Primacord in front of 
and about an inch away from the heavy glass protec- 
tive window, just above and below the held of view 
of the camera. The Primacord fuzes are of such length 
that they detonate several microseconds after the 
flash bulb. The opaque products from the Primacord 
expand in front of the camera lens and effectively 

^The discussion of shaped charges is from a summary pre- 
pared by M. A. Paul. The discussion of the remaining items 
in this chapter is based on information supplied by G. H. 
Messerly. 


close it. The shutter remains closed because of the 
formation of a layer of soot and carbon on the heavy 
glass window. The detonating fuze next to the window 
is covered with a layer of vaseline and carbon black 
to increase its effectiveness for this purpose. 

A second extension of the flash photography tech- 
nique is concerned with the development of a rela- 
tively long-duration light source for use in conjunc- 
tion with the drum or mirror camera to obtain rate 
pictures of rapidly moving nonluminous phenomena — 
water shock waves, for example. To produce the in- 
tense light of 40 to 50 microseconds duration neces- 
sary for this purpose, the light bulb is made in the 
form of a transparent tube filled with argon with an 
explosive pellet at one end of the tube. (An earlier 
form of the light had a narrow column of explosive 
at the axis of the tube.) 

The flash photographic method has been applied 
to a variety of explosive phenomena, for example, the 
formation of jets from cavity charges and the quali- 
tative and quantitative aspect of expanding shell cases. 
These and other applications are described in detail 
in the reports already cited. 

Shock waves in air and in water were investigated, 
using both the rotating drum camera^ and flash pho- 
tography. The data obtained have been presented in a 
formal report.^ The principal interest in the work 
lies in the fact that quantitative observations were 
made of much more intense shock waves (shock-wave 
pressures of the order of hundreds of atmospheres in 
air) than are customarily studied by other means. 

4 2 STUDIES OF SHELL FRAGMENTATION 

In order to study and compare the effectiveness of 
various shells or bomb casings and fillers, it is neces- 
sary that data be available on (1) the average frag- 
ment velocity and the fragment velocity distribution 
at various directions with respect to the shell axis; 
(2) the mass and size distribution of the fragments, 
also as a function of direction from the shell; (3) 
the retardation coefficient for the fragments, i.e., the 
rate at which their velocity decreases due to air re- 
sistance; and (4) standard target damage data for 
fragments of various sizes and velocities. If suffi- 
ciently accurate and detailed data of this kind are 


(( JtVfTUKVTIATr^ 


65 


66 


EXPERIMENTAL STUDIES OF EXPLOSIVE PHENOMENA 


available, it is possible to make reliable predictions 
of the effectiveness of shells against various kinds of 
targets and at different target distances. The pro- 
gram of study at the Explosives Eesearch Laboratory 
[ERL] was designed to supply such data. 

The method of fragment velocity measurement de- 
veloped at the ERL measures the velocities of a num- 
ber of fragments from a single burst whose trajec- 
tories are defined only within a known solid angle. 
It consisted of recording, with a rotating drum cam- 
era, the shadow images of the fragments passing 
between the camera and three illuminated slits. The 
three image spots produced by each of a number of 
fragments passing in front of the camera at about the 
same time are easily identified, and the fragment 
velocity is deduced from their spacing on the film.® 

The individual fragment velocities were measured 
with an error of about ±2%. The velocity measure- 
ment was made over a distance of 2 ft at an average 
distance of 8^2 ft from the shell. After passing in 
front of the camera, the representative group of frag- 
ments were received on a target which recorded their 
penetrative power. If this target was made of wood, 
telephone books, or other suitable material, the in- 
dividual fragments were preserved and identified with 
the measured velocities. The method thus gave, for 
each fragment of a representative group from a bomb 
or shell burst, a measurement of the mass and ve- 
locity; and, depending on the amount of distortion 
which the fragment suffered when it is stopped, the 
fragment size and shape. Further, from the change 
ill ajipearance of the image spots from one slit to the 
next, it was possible to make a rough estimate of the 
rotational velocity of the fragment. 

The shell to be studied was detonated in the center 
of a 20x20-ft chamber, with the shell axis vertical 
and the center of the shell about 2 ft from the floor. 
A band of fragments 15 degrees in width and from 
1 to 2 ft high was used for the velocity measurements, 
l^enetration and fragment distribution measurements 
were made at the same time on a large portion of the 
side wall band of fragments by means of targets 
placed around the sides of the room. From a single 
burst it was thus possible in principle to obtain com- 
plete information on the fragmentation of a given 
shell. Because of the spread in fragment velocity, how- 
ever, it is usually necessary to fire about six shells to 
obtain a statistically significant average velocity value. 

As indicated above, in order to predict the useful 
range of the fragments, something must be known of 
their deceleration from air resistance. To provide such 


data, the single-station apparatus described above was 
expanded to allow velocity measurements to be made 
at three distances, 914, 2514, and 78 ft from the 
shell. The experimental arrangement for these meas- 
urements, and the results obtained are described in 
reference 6. 

Some data on the size distribution of the fragments 
may be inferred from the distribution of hit sizes on 
the steel target panels, and a smaller number of data 
on the actual fragments were obtained from the frag- 
ments recovered from the wood targets. It is much 
more efficient, however, to obtain the mass and size 
distribution of the fragments from pit firing in which 
all the fragments from a given shell are received in 
sand or sawdust and recovered therefrom.'^'^ 

From the foregoing it seems that in principle, at 
least, all the requisite data for the evaluation of a 
shell may be obtained. The actual results, however, 
summarized below, are far from complete and con- 
stitute only a beginning in the study of this subject. 

In a study whose main purpose was the determina- 
tion of the effect of casing thickness on the fragment 
velocity and penetration, simulated shells of 2-in. ID 
and wall thickness of Vg, V2, and % in., 

filled with TNT, Ednatol, Cyclotol, and Torpex, were 
studied. In addition a number of other explosives 
were studied in y2-in. thick cases. It was found^® that 
the average fragment^ velocity was a nearly linear 
function of (charge weight/casing weight) ® a con- 
clusion later confirmed over a wide range of charge 
ratio by flash photography studies.^ 

The relatively small amount of data on fragment 
retardation may l)e summarized. 

1. The maximum or mean fragment presentation 
area per unit mass of fragment does not seem to be 
a very useful criterion for predicting fragment re- 
tardation. (This remark applies only to fragments of 
the indicated size and velocity range and over a dis- 
stance range of 27 ft from the shell. Studies with 
smaller fragments and/or larger distances would un- 
doubtedly show some dependence, and research in 
this direction should certainly be undertaken.) 

2. About Vs of the fragments studied exhibited ap- 
preciable rotation, while % were stably oriented. 
This fact suggests that it is not very useful to apply 
to the problem of fragment retardation a mathemat- 
ical analysis which postulates random orientation of a 
given fragment with respect to its direction of flight.^^ 

The relative effectiveness of different explosives in 

‘’Controlled fragmentation of thin-walled casings is dis- 
cussed in Reference 11. 


(i li\ I'l IiI'.XtITD 


SHAPED CHARGES 


67 


the same casing was examined for Ednatol, 55/45 
TNT/Alnminnm, Cyclotol, HEX, PTX-l, VTX-2, 
TNT-D2 95/5, Tritonal-I)2 95/5, Picrotol 52/48, 
Pipe, Torpex II, Pentolite, Composition A-3 91/9, 
Composition A 88/12, Amatol 80/20, and TXT. The 
last-named explosive was used as a control. Maximum 
average fragment velocity ditferences of about 25% 
were found among the various explosives. The dif- 
ferences in average velocity showed in most cases a 
fair correlation with the number of fragments of 
various degrees of etfectiveness and with the ballistic 
mortar value for the explosive in question.^^ 

In an attempt to place the data for target damage 
on a more systematic basis, an attempt was made to 
determine, for several velocities and target thick- 
nesses, the smallest fragment mass which will just 
perforate, and the largest mass which will just fail 
to perforate a given target. The results of voluminous 
target penetration data bearing on this problem have 
been collected together with frequently useful for- 
mulas relating the fragment momentum per unit 
area to the penetration in targets of wood, paper 
(telephone directories), and steel, and the average 
mass and area of shell fragments. 

Both the single and the multiple station velocity 
apparatus were used to compare the effectiveness of 
explosives in various types of actual shells.^®'^® 

A target damage study program was made with 
the objective of determining the optimum wall thick- 
ness of mortar shells designed for use with proximity 
fuzes.^^ The experimental setup used for these static 
firing tests consisted of two 9-ft high semicircular 
target “^Tences” of 1-in. thick yellow pine. One of the 
semicircular target fences was of 20-ft radius; the 
other of 40-ft radius. The shell was hung at the com- 
mon center of the semicircular targets, with the shell 
axis horizontal, and in line with the common diameter 
of the semicircles so that equivalent fragments were 
received on both targets. This work was necessarily 
done in a proving ground area. 

The significant results of the investigation may be 
summarized : 

1. There is little difference in effectiveness or ap- 
preciable shift of fragment distribution with change 
in wall thickness of 0.050, 0.060, 0.080, 0.090, and 
0.110 in. 

2. Change from nose to tail imitation shifts the 
peak in fragment distribution from about 100 to 80° 
(nose = 0°). 

3. Composition B is 10 to 15% more effective 
than TXT. 


43 SHAPED CHARGES 

Introduction 

The discovery of the shaped charge or cavity effect 
is generally attributed to C. E. Munroe, a civilian 
chemist working for the U. S. Xavy at the time. 
In several papers published during the period from 
1885 to 1900 he showed that a cavity hollowed in the 
base of an explosive charge resulted in a deep hole 
instead of the usual shallow depression in a steel plate 
on which the charge had been standing. The phenom- 
enon was reinvestigated in Germany in 1914 by E. 
Xeumann, who studied the effect of varying the cavity 
shape and observed that penetration persisted when 
the charge was removed a short distance from the tar- 
get. Xo use, however, was made of shaped-charge 
weapons during World War I. 

The basis of modern shaped-charge developments 
is the introduction by H. Mohaupt in 1937 of a 
metal liner in the cavity. With a suitable metal liner, 
the depth of the hole in the target may be increased 
more than threefold over that produced by an unlined 
cavity charge. Furthermore, the lined charge is effec- 
tive at a considerably greater distance from the tar- 
get ; for the conventional liners now in use, a stand-off 
of several charge diameters is required to attain maxi- 
mum depth of penetration.^ 

Shaped-charge weapons have been extensively used 
in World War II by all major armed forces. Research 
on shaped charges in this country, particularly on 
the part of the Xational Defense Research Committee 
was stimulated by pioneer work in Great Britain to 
Avhich Ave are deeply indebted 

American shaped-charge Aveapons that have been 
in Service use include the M9A1 rifle grenade, the 
spectacularly successful M6A3 2.36-in. HEAT rocket 
(the Bazooka), the M307 HEAT shell for the 57-nini 
recoilless gun, the M66 and M67 HEAT shell for the 
75-mm and 105-mm howitzers, and several Engineers’ 
demolition charges. Weapons in various stages of de- 
Anlopment, but not completed in time to be applied 
by the Armed Services include a shaped-charge tor- 
pedo Avarhead, a HEAT round for the 4.2-in. recoil- 
less chemical mortar, shaped-charge bombs of various 
sizes, a high-velocity 2.36-in. HEAT rocket, and sev- 
eral other projectiles of different sizes. 

®The early developments are described in reference 27. 

•^Excellent reviews of British work are to be found in refer- 
ences 28 (a review to the end of 1942); 29 (the early part of 
1943); 30 (the period from August 1943 to August 1944); 
and 31 (this includes ARD Explosives Report 669/44). 


68 


EXPERIMENTAL STUDIES OF EXPLOSIVE PHENOMENA 


Division 8 sponsored tlic developineiit of several 
speeific sliaped-eharge weapons, described in Uhap- 
ter 3. 

F\indaniental researeli on shaped eliarges by Divi- 
sion 8 was carried on at the Explosives Itesearch Lab- 
oratory, Brnceton, Pennsylvania, which also partici- 
pated directly in certain specific shaped-charge weap- 
on developments. 

In the general description of shaped-cliarge phe- 
nomena that follows, we have l)orrowed freely from 
British sources of information and also from work in 
this coimtiy carried on at the Eastern Lahoratory of 
the du Pont Company nnder contract with the Army 
Ordnance Department, and at the Ballistic Besearch 
Lahoratory, Aberdeen Proving Ground, Maryland. 
Tlie present state of onr knowledge has been derived 
from many sources and we do not pretend in this snm- 
mary report to have assigned full credit to all the 
various organizations and individuals who have con- 
tributed to this knowledge. 

^ General Properties of Cavity Charges 
Fired in Air 

Cavity charges bred against steel or concrete tar- 
gets in air produce, typically, holes several calibers 
deep and rather small in diameter in the target. If 
they fail to perforate the target, no special damage is 
done on the other side. If they do perforate the tar- 
get, they will disintegrate objects directly in the line 
of fire, that is, along the extended charge axis. Fur- 
ther damage may he done by spalled material from 
the rear of the target, but such damage is generally 
confined to a region of perhaps 20° solid angle 
about the line of intense destructive effect. An im- 
])ortant source of damage consists of explosions or 
fires that may be initiated by the jet if it should pass 
through a magazine or a fuel supply. 

The effectiveness of a propelled shaped-charge weap- 
on, unlike that of an armor-piercing projectile, is a 
pro])erty of the charge itself and not of the velocity 
with which it strikes the target. In fact, for reasons 
to he considered later, the effectiveness is actually 
less at higher velocities. The shaped-charge is there- 
fore ideally suited to low-velocity projectiles, such as 
the Bazooka, and to stationary demolition charges. 
The armor-})iercing projectile, on the other hand, by 
carrying the main charge through to the other side 
of the target, will do more general damage there. 

Explosive Filling and Cjiapge Length 

In general, the depth of penetration by a cavity 
charge increases with the power of the exjffosive ffll- 


ing. Last (V)mposi(ion B is about 20% more effec- 
tive tban cast TNT. One of the most effective ex})lo- 
sives is fluid 10/30 ('yclotol. For lilling small weap- 
ons, this latter composition is too thick (it must flow 
evenly into the narrow converging space at the base 
of the liner), and 05/35 Gyclotol is more acceptable.^- 
For historical reasons related to the supply of BDX 
and also to questions of fluidity, many American 
shaped-charge weapons, including even the howitzer 
shell, have been loaded regularly with cast 50/50 
Pentolite. The depth of penetration with Bentolite 
is only 00 to 05% of that obtained with 65/35 Cy- 
clotol ; at the same time, Bentolite is a more sensitive 
tilling. Ihcatinny Arsenal has recently developed 
the ternary mixture ]>TX-2 ( PETN/BDX/TNT 

25/44/28) as a castable filling for shaped-charge ap- 
plications, but it has not yet been adopted for general 
service use. The Germans have made much use of 
charges consisting of pressed preformed pellets of 
waxed BDX and other explosives. 

As the charge length, measured from the liner base, 
is increased, the cavity effect approaches a limit at- 
tained at a charge length of about 3 diameters. When 
the charge length is increased further, there is little 
increase in depth of penetration. F'igure 1, for un- 
confined 1%-in. diameter charges bearing MOAl steel 
cones, is illustrative. The charges consisted of 50/50 
cast Pentolite topped by pressed tetryl booster pellets 
% in. in length. The charge length in Figure 1 in- 
cludes the booster. 



CHARGE LENGTH CONE DIAMETERS 


Figure 1. Dejitli of penetration versus charge length 
iinconfined, 1^-in. diameter charges bearing MOAl 
steel cones at 3-in, stand-off. 

The shaped-charge effect depends uj)on a concen- 
tration of the energy normally leaving the end of the 
charge. Flxccqit for the rather small loss in charge 
weight due to the presence of the cavity, the general 
blast and fragmentation effects of a cavity charge are, 
therefore, practically the same as for an ordinary 
charge of the same size. Thus, the M6A3 2.36-in. 
HEAT rocket is an excellent fragmentation grenade. 
In fact, comparative tests made with an experimental 


CmMMlU:.NTLU!> 


SHAPED CHARGES 


69 


fragiiioiitatioii head in })lac‘e ol' the shaped-eliarge 
head showed that the original sliaped-eharge head was 
actually superior for fraginentation. The presence of 
the cavity, of course, had nothing to do with tlie 
superiority, which was due to the rather liigii charge 
weight to casing weight ratio as compared with the 
conventional heavy-walled grenade; but it is evident 
that one need not sacrifice ordinary high-explosive 
elfectiveness to any appreciable extent in order to ob- 
tain tlie advantage of the cavity effect. 

Stand-Off 

Most cavity charges show an increase in depth of 
penetration when the stand-off, or distance between 
liner base and target, is increased from zero to some 
optimum distance, which is of the order of several 
charge diameters. Exceptions are unlined charges and 
charges bearing 20° steel cones; these perform best 
at zero stand-off. For all other lined charges, the 
optimum stand-off increases as the cone apex is in- 
creased. Typical depth of penetration versus stand-off 
curves for steel conical liners of 1%-in diameter in 
unconfined charges are shown in Figure 2. For steel 


CONE DIAMETERS 



Figure 2. Effect of stand-off on depth of penetration, 
\%-m. diameter iinconfined cone charges. 


hemispherical liners, the optimum stand-off is 13.5 
to 4.0 charge diameters.^^ At stand-offs in excess of 
the optimum, depths of penetration are likely to be 
erratic ; occasional charges that are presumably excep- 
tionally well aligned give depths equal to those ob- 
tained at the optimum stand-off. Penetration with 
diminished effectiveness persists out to amazingly 
large distances from the charge. Thus, one can design 
charges that will penetrate one charge diameter of 


mild steel at a stand-off of 15 charge diameters. Alu- 
minum liners show much larger optimum stand-offs 
than do comparable steel liners. 

The hole volume changes but slightly as the stand- 
off is increased to the optimum for depth of penetra- 
tion. The improvement in depth is obtained at the 
cost of some reduction in hole diameter. With increas- 
ing stand-off beyond the optimum, the average hole 
volume shows a decrease. A theory of the effect of 
stand-off upon target penetration is given in Sec- 
tion 4.3.4. 

Lined Thickness 

The optimum liner weight varies but slightly with 
the apex angle for conical liners of given base diam- 
eter. The optimum liner thicl'ness for a given metal 
is thus proportional to the sine of half the apex angle, 
though it may be somewhat greater for cones more 
acute than 45°. While exhaustive tests have not been 
carried out on metals other than steel, the evidence 
available indicates that the optimum weight is not 
very different for different metals, including copper 
and aluminum as well as steel. At any rate, the per- 
formance is not affected critically by the precise liner 
weight.^'^ 

The optimum liner weight and thickness are greater 
for confined than for unconfined charges. In fact, the 
])erformance of cones that are of optimum wall thick- 
ness in unconfined charges is seriously impaired it the 
charges are confined. On the other hand, cones that 
are somewhat heavier than the optimum for uncon- 
fined charges show an improved performance when the 
charges are confined. Optimum Avail thicknesses for 
45° steel cones under several degrees of confinement 
are summarized by the following data. 

Approximate Optimum 
Wall Thickness for 45° 
Cones (per cent of 

Confinement base diameter) 

None or very light 1.5 

Light (cross-sectional charge /casing = 1.3) 2.5 

Heavy (cross-sectional charge/casing = 0.4) 3.5 

The conrmement referred to as light corres})onds to 
that in a rocket head such as the M()A3 2.3()-in. 
HEAT rocket. The condition referred to as heavy cor- 
responds to that in a shell such as the MG6 75-mni 
HEAT shell. The optimum Avail thicknesses given are 
about right also for copper 45° cones. 

If one chooses the appropriate optimum cone 
AA^eight, confinement has no net effect upon the depth 
of penetration. Increased confinement does increase 
the hole diameter and hole volume. Other conditions 




70 


EXPERIMENTAL STUDIES OF EXPLOSIVE PHENOMENA 


being constant, increased liner thickness results in 
smaller diameter holes. 

Linp:r Shape 

Liners of various shapes have been tested in small- 
scale charges. Except for differences in optimnm 
stand-off, a wide variety of shapes appear to be equiv- 
alent. No special shape has been discovered that is 
superior to a cone of uniform wall thickness with 
apex angle between 45° and 80°. Figure 3 summarizes 
the depth of penetration versus cone angle relations 
for steel-lined unconfined 1%-in. diameter Pentolite 
charges. At zero stand-off, 20° cones give the best re- 
sults of all angles tested, about 3.0 cone diameters in 
mild steel. Better results, about 3.7 cone diameters in 
mild steel (equivalent to about 3.1 in armor), are ol)- 
tained at 2-in. (1.2 cone diameters) stand-off using 
45° cones. With unlimited stand-off (e.g., 3 cone 
diameters), still better results, about 4.0 cone diam- 
eters in mild steel (3.2 in armor) are obtained with 
60° cones. These maximum depths may be increased 
by about 10 per cent by using 65/35 Cyclotol in place 
of Pentolite. Since in most propelled weapons, stand- 



Figure 3. Depth of penetration versus cone angle; steel 
cones, unconfined l^^-in. diameter Pentolite charges. 

offs much in excess of 1-cone diameter are difficult to 
obtain, 45° cones appear to be the best choice for such 
weapons. In stationary demolition charges, however, 
where stand-off may be readily controlled, 60° cones 
appear to have a small advantage over 45°. 

Cones with tapered wall thickness have received 
some consideration. For 45° cones, a taper from thin 
at the apex to thick at the base has an advantage over 
a taper from thick at the apex to thin at the base, but 
neither appears to have any advantage over a cone of 
uniform wail thickness. British sources, however, in- 


dicate that a great improvement in the performance 
of 80° lead cones results from a change from uniform 
wall thickness to walls tapering from thin at the ai)ex 
to thick at the base.^® 

Hemispherical steel liners behave much better in 
confined charges than in unconfined ones. A remark- 
able improvement has been observed as the result of 
the presence of an axial Hash tube (for point-initia- 
tion by a spit-back fuze) but the reason for this phe- 
nomenon is not at present known. Hemispherical 
steel liners are characterized by rather large optimum 
stand-offs (3.5 to 4.0 diameters) and are quite inef- 
fective at stand-offs of the order of 1 diameter. Steel 
spherical cap liners with large radii of curvature are 
ineffective, but British sources indicate that similar 
liners made of lead perform well. 

The configuration of the base of the liner where it 
joins the casing is of some importance. If the true 
cone base diameter is smaller than that of the charge 
and if the cone is supported by a flat base flange cov- 
ered by explosive, the performance is seriously im- 
paired under certain conditions. In general, for a 
charge that is confined, the true cone base should be 
the full diameter of the charge at the place where the 
cone is secured to the casing. The harmful effect of 
the base flange when covered by explosive appears to 
be related to interference with development of the 
later parts of the shaped-charge jet, normally formed 
from material coming from near the base of the col- 
lapsing liner.^^ 

Liner Material 

I'or rather obvious reasons, most shaped-charge 
projectiles have been equipped with steel liners. The 
steel should be a mild steel of low carbon content since 
carburized steel, probably because of its greater brit- 
tleness, gives inferior results. Certain service demo- 
lition charges, such as the M2 shaped charge, have 
been provided with glass cones. Glass is somewhat in- 
ferior to steel in depth of penetration, but the hole 
volumes produced in concrete targets are larger and 
the holes are less filled with debris.^®’^^ 

Since copper became more available, considerable 
progress has been made in the development of cop- 
per liners, resulting in the adoption in April 1945 of 
copper cones for the 2.36-in. HEAT rocket (the 
Bazooka). This development was carried on by the 
Eastern Laboratory of the du Pont Com})any under 
Army Ordnance Department contract. Earlier work^® 
with unconfined 1%-in. diameter charges had indi- 
cated a rather large optimum stand-off for copper, 




SHAPED CHARGES 


71 


even thougli ('opjHM' was siijK'riur to slorl at sliortor 
staiul-otl's.^’ ^loro rtHriit work witli c' 0 |)})or M() ooiies 
in c-oiitinod c‘liar»»es (as in the 2.o()-in. rocket head) 
sn^ijests tliat the optiinnni stand-otV is about tlie same 
as for steel, namely about 2 cone diameters for 
cones. Deptli of })enetration versus stand-otf curves for 
steel and copper ^IG cones are shown in Figure 4. 

Fp to the optimum stand-otf, tlie depth of penetra- 
tion l)v tlie cojiper cones is about 40 per cent greater 



Figure 4. Depth of penetration versus stand-off, IMG 
steel and copper cones (2.36-in. diameter, 0.0G2-in. 
wall 1^-in. diameter aluminum 4o° cones (0.0G4-in. 
wall), all charges steel confined. 

than for steel. The maximum depth of penetration is 
about 5 cone diameters in mild steel or about 3.8 cone 
diameters in homogeneous armor using Fentolite 
charges. With 05/35 Cyclotol, these maxima may be 
increased liy about 10 ])er cent. The relative superior- 
ity of copper over steel appears to be somewhat less 
in an armor than in a mild steel target. At stand-olfs 
beyond the optimum, according to Figure 4, the ad- 
vantage of copfier over steel disappears, though in 
penetrating through ecpially large thicknesses of \vater, 
copper remains superior to steel. No reason is known 
why large distances through air should influence the 
relative performances of copper and steel cones dif- 
ferently from large distances through water. For that 
matter, no generally aci'epted explanation has lieen 
offered for the quite inqiressive superiority of cop])er 
over steel at moderate stand-olTs. One suggested ex- 
planation is based on the greater ductility of copper, 
presumably maintained even under high stress, which 
may result in more material being pulled from the 
base of the liner after collapse is complete in the so- 
called ^^secondary” phase of jet formation. This mate- 
rial would add to the latter portion of the jet and 
thereby increase the overall penetrating power. 

Aluminum liners are peculiar in that they show re- 
markably large optimum stand-offs. Figure 4 shows 


this for 45° aluminum cones. At tlieir ojitimum stand- 
off of 0 to 8 cone diameters, penetration by the alu- 
minum cones is about equivalent to the maximum for 
steel cones. At stand-offs of 1 to 2 cone diameters, how- 
ever, wiiere steel and co])pcr are most effective, alu- 
minum is quite ineffective. Aluminum cones show a 
dependence of optimum stand-off on cone angle similar 
to that observed with steel cones, but for any given 
angle the optimum for aluminum is displaced to a 
much larger value than for steel. No plausible explana- 
tion of the stand-off effect with aluminum has been 
offered. The obvious correlation w4th low liner density 
breaks down when one considers glass cones which 
show no such effect. 

German sources have indicated that die-cast zinc 
has merit as a shaped-charge liner material, though 
it is not in the same class as copper. 

The llritish, early in World War If, drew^ a distinc- 
tion between “fluid’’ and “particle” jets.^^’"*® be- 

lieved that the more volatile metals such as lead, tin, 
and cadmium gave rise to fluid jets, wdiereas steel 
gave rise to a stream of discrete particles. At one time 
they regarded the fluid jets as having appreciably 
greater penetrating power than the particle jets. 
The comparison however w^as based upon shallow 
dish-shaped liners. We know that such liners made of 
steel are greatly inferior to acute cones, whereas when 
made of lead they give reasonably good performances. 
We believe it is correct to state that none of the so- 
cial led fluid types of liners is superior to the better 
steel cones. The distinction between tlie ])roperties of 
fluid and particle jets was based to a considerable 
extent upon the shapes of the holes they produced in 
the target. We know now that the hole size and shape 
reflect only in a very indirect way the shape of the 
jet, depending rather upon the nature of the target 
and the rate at which momentum is delivered to it. 
The nature of jet formation by steel cones has lieen 
greatly clarified by flash radiographic investigation. 
The steel jet certainly appears to be formed in a man- 
ner reminiscent of the behavior of true liquid jets 
and the theory of its formation is actually based upon 
hydrodynamic principles. Whether the jet itself con- 
sists of a continuous quasi-liquid stream or a succes- 
sion of small discrete particles is not definitely known, 
l)ut the question is probaldy meaningless. The distinc- 
tion between the flow of a true liquid and that of a 
solid under conditions of extremely high stress is 
rather difficult to define in terms of effects upon the 
surroundings. For the so-called fluid metals of the 
British investigators, the relatively low melting and 


(('OyriDI-fNTIALj 


EXPERIMENTAL STUDIES OF EXPLOSIVE PHENOMENA 


boiling })oints make it reasonably certain that the 
liners actually are melted and, perhaps, to a certain 
extent even vaporized during jet formation. We 
slionld expect that if appreciable conversion to the 
vapor state takes place the resulting jet will have a 
tendency to ditfnse more rapidly with increasing dis- 
tance from the target than wonld the jet from a metal 
that shows a greater tendency to cohere. Flash radio- 
graphic investigation should provide the answer to 
this point, as well as to the question why lead dish- 
shaped liners are so much more effective than liners of 
similar shape made from steel. 

A special use was found for composite liners con- 
sisting of sand particles bonded by a thermosetting 
plastic matrix molded to shape. The object was to 
demolish beyond recognition a small radar oscilla- 
tor, located within a container. A steel-lined cone 
charge of conventional design wonld merely drill a 
hole through the unit but leave it otherwise recogniz- 
able. The sand liner, by producing a more diffuse if 
less penetrating ^‘jet,^’ was completely effective in dis- 
integrating the target. This application is discussed 
in Section 3.6. 

Takget Material 

For experimental purposes, many shaped-charge 
tests have been made using mild steel targets, but 
homogeneous armor and reinforced concrete are the 
principal target materials against which most actual 
weapons are designed to be effective. For quite a wide 
range of steel cones, the depth of penetration in homo- 
geneous armor averages about 84 per cent of the 
depth in mild steel. For copper cones, however, the 
ratio appears to be somewhat smaller, about 74 per 
cent for copper M6 cones. The hole diameters in 
armor are about 80 per cent of the diameters in 
mild steel. 

For lack of adequate test facilities. Division 8 did 
no work with shaped charges against reinforced con- 
crete. A large body of information is available 
through the work of the du Pont Eastern Laboratory 
in designing shaped demolition charges for the En- 
gineer Board (contracts W-145-EXCf-467 and W-670- 
OliD-4331).^*’^^'^^ The depth of penetration in re- 
inforced concrete is ronghl}' 3.2 times the depth in 
homogeneous armor for the glass-lined M2 shaped 
demolition charge. 

Scaling Laws 

Such experimental evidence as is available for large 
shaped charges indicates that they satisfy a linear or 


IIoi)kinson scaling law. If one increases all ot' the 
charge dimensions in a fixed proportion, including 
diameter, liner thickness, charge length and stand-off, 
the depth of penetration in a given target material 
also increases in the same proportion. Fairly good 
evidence of this for a spaced target was obtained in 
an investigation dealing with the design of shaped- 
charge bonibs.'*^ 

A JiER RATIONS IN CaVITY CHARGES 

Cavity charges are peculiarly sensitive to any dis- 
turbances in symmetry. They are, therefore, more 
touchy than ordinary charges with respect to design, 
manufacture, and loading. Thus, if the cone® is in- 
clined by as much as 1° or displaced by as nincli as 
of the diameter with respect to the charge axis, 
a significant impairment of the depth of penetration 
follows.®® The liner itself must show no variation in 
wall thickness in a plane normal to the axis, though 
axially symmetrical variations from apex to base may 
be tolerated to some extent without causing injury 
to the performance. Some difficulty has been experi- 
enced in obtaining liners for experimental purposes 
having reproducible qualities. Bather subtle varia- 
tions in liner quality may result in differences in 
penetration of as much as 20^ . The production of 
steel and copper liners in quantity showing reason- 
ably uniform behavior has been solved by the opera- 
tion of successive drawings, nine draws being used to 
form the 45° M6 and MOAl cones. Even then, small 
variations in the behavior of different production lots 
have been observed. 

The explosive charge must be of unusually high 
quality to ensure satisfactory shaped-charge perform- 
ance. Penetrations as poor as 50^ of normal have 
been observed in a lot of Service-loaded Bazookas 
containing the normal Pentolite filling that were 
found by radiographic inspection to have holes in the 
castings. xV significant difference has been noted in 
the performance of 70/30 fluid Cyclotol, depending 
upon the manner in Avhich the charges are cast. This 
explosive is rather viscous for loading small charges 
and gives a performance no better than that of Pen- 
tolite if loaded in the usual way in cold molds or cas- 
ings. If the molds are preheated and the centers of 
the charges kept open by use of risers and steam 
fingers to eliminate contraction cavities, the perform- 
ance is improved by as much as 20^,. 

The effects of these aberrations as well as of certain 

^Variations in the thickness and quality of the cones can be 
detected by a radiographic technique.^! 


roxrtiiFATi VlJ 


SHAPED CHARGES 


73 


others, such as wires through the cone and charge 
(for electromagnetic point initiation), have been dis- 
cussed in detail.^- Other interesting experiments on 
similar lines have been carried out by du Pont East- 
ern Laboratory 

Effhct of Spixxixg 

A serious deterrent to the development of shaped- 
charge shell has been the general deleterious effect 
of spinning upon the depth of penetration. For some 
time, this effect was not recognized in this countiw, 
though tests conducted by the British had shown its 
existence.^^ In fact, the HEAT shell for the 57-mm 
recoilless gun Avas designed by the Small Anns Dm- 
sion of the Ordnance Department AA'ith the expecta- 
tion that it would supplant the Bazooka. Tests that 
had been conducted previously at the ExplosiACS Be- 
search Laboratory showed that a depth of penetration 
only half that of a nonspinning round of the same 
caliber could be expected. The problem Avas for 
some time obscured by the question of fuze perform- 
ance and attainment of adequate stand-off at mod- 
erately high velocities (of the order of 1,200 fps). 

The general effect of spinning at such rates as are 
necessary to stabilize projectiles at velocities of 1,200 
fps is to reduce the depth of penetration by conical 
liners at optimum nonspinning stand-off by about 
50%. At zero stand-off, the effect of spinning on 45° 
cones is less, but then one loses the advantage nor- 
mally obtained in a nonspinning charge with in- 
creased stand-off. IVith still higher rates of spin, the 
penetration apparently levels off and no further re- 
duction beloAv about 50% folloAvs. On the other hand, 
the effect begins even at rather Ioav rates of spin, so 
it is not feasible to reduce the tAvist or muzzle A^elocity 
of the gun unless one is Avilling to go to such ex- 
tremes as to alter altogether the tactical uses of the 
AA'eapon. One cannot eliminate the effect by changing 
the cone angle, since even 20° cones are affected at 
zero stand-off (in this case, the jet has some distance 
to travel Avithin the cone before it strikes the target). 
The effect is no doubt due to centrifugal force acting 
to reduce the concentration of the normally extreme- 
ly small-diameter jet. Flash radiographs of spinning 
cavity charges taken at the Ballistic Research Lab- 
oratory shoAv this.®® 

One general recommendation of Division 8 Avas 
that serious consideration should be given to high- 
velocity shaped-charge projectiles stabilized by fins. 
No action along this line Avas taken until very late 
in the war and no such projectiles have been devel- 


oped in time to be of use to the Services. At the same 
time, since the tendency has been in the opposite 
direction, to stabilize even the rocket-propelled pro- 
jectiles by spin, intensive research was undertaken to 
discover liners less affected by spin and eA^en to devise 
liners specially modified to counteract the effect of spin. 

Hemispherical liners showed some early promise, 
and indeed the effect of spin appears to be more 
gradual Avith hemispherical than with conical liners, 
so that Avith reduced muzzle A^elocity or reduced twist 
some improvement over conical liners could be ex- 
pected. Such liners, made of copper, were actually 
adopted in the shell, HEAT, M307, 57 mm, but with 
the present tAvist and muzzle velocity of the 57-mm 
recoilless gun, these liners are probably not superior 
to a AA’ell-designed conical liner. These results are 
confirmed by spinning tests conducted by J. C. Clark 
and C. E. HaAAL at the Ballistic Research Labora- 
tory.®® The Germans used a hemispherical steel liner 
in their 105-mm and other holloAA'-charge hoAvitzer 
shell. Although, according to recently captured docu- 
ments, they discovered the deleterious effect of spin- 
ning quite early in the AA^ar, they apparently made no 
determined effort to do anything about it. 

In the direction of designing a liner specially modi- 
fied to compensate for spin, partially successful re- 
sults haA^e been obtained at the Explosives Research 
Laboratory using a so-called offset liner.®’^ The depth 
of penetration of such a liner is actually improved 
OA’er the static performance when the shell is spun. 
As Avould be expected, the static performance is be- 
loAV that of an unmodified liner and spinning in the 
Avrong direction impairs the performance beloAv that 
of the static charge. AVhen spun, however, in the 
proper direction at the optimum speed, which in 
principle depends upon the degree of offset, penetra- 
tions have been obtained that are significantly better 
than those obtained Avith conventional conical liners 
at the same rotational speed, though still inferior to 
those of nonspinning conical liners. These initial off- 
set liners hoAA'ever were far from perfectly constructed, 
both in actual detail, AAdiich shoAA^ed some asymmetry 
in the dies used to form the liners, and in principle, 
in that the average degree of offset impressed was 
not ideal for the given liner shape. Considerable im- 
provement can be expected from future research ef- 
forts along this line. 

Lixear Cavity Charges 

Linear caAuty charges bearing re-entrant, wedge- 
shaped liners may be used to produce linear cuts in 


tiiXFiD K yriAil 


74 


EXPERIMENTAL STUDIES OF EXPLOSIVE PHENOMENA 


the target."’*”"’® 44ie maximum depth ot the eiit in 
mild steel ai)})ears to be about 0.8 charge width. For 
this application, wedges with 45° apex angle appear 
to he completely ineffective. The approximate opti- 
mum conditions for various stand-off's are as follows: 


Stand-off 
(charge widths) 

0 - 0.3 
0.6 
1.0 
1 . 2 - 1. 4 


Best Liner Shape 
and yiaterial 

80 ° steel 
80 ° Steel 
120° steel 
80 ° aliiminuin 


Wall Thickness 
(charge width) 

0.02 

0.03 

0.03 

0.06 


Beyond charge-target distances of about 2 charge 
widths there appears to be no liner that has appre- 
ciable penetrating power. 


G K N EJtAL Application s 

For antitank applications, the best shaped-charge 
weapons developed to date have been low-velocity 
projectiles such as the M9A1 rifle grenade and the 
M6A3 2.36-in. rocket. These projectiles are rather 
small and we may anticipate the development of 
larger shoulder weapons. With the high-velocity T59 
2.36-in. rocket motor, for example, one could design 
a 3y2-iii* shaped-charge head that would still have 
about the same velocity as the present Bazooka and 
would defeat 12-in. armor. On the other hand, the 
same motor could be used with a head no larger in 
diameter than that of the present Bazooka to give a 
higher velocity and larger effective range. We may 
anticipate the development of fin-stabilized shaped- 
charge projectiles fired from recoilless guns with 
velocities in excess of 1,000 fps. We may expect prog- 
ress from the development of special liners compen- 
sated for spin. Even if the effect of spin could be 
neutralized, however, there is probably little future 
in high-velocity shaped-charge projectiles (of 2,700 
f})S or more velocity), since, when high muzzle veloci- 
ties are available, true armor-piercing projectiles 
l)resent a better choice. 

Shaped demolition charges for attacking concrete 
fortifications are available. These are particularly 
useful in preparation for a follow-up attack with 
Bangalore torpedoes or other demolition charges 
placed in the holes. Large rocket-propelled shaped 
charges should he useful wea])ons for attacking con- 
crete in situations where guns and anticoncrete shell 
are not available. Some progress has been made in 
developing such projectiles. 

The Ordnance Investigation Laboratory has made 
effective use of small linear cutting charges in sec- 


tioning loaded projectiles and oj)ening mines for 
examination.^*’'’® 

General Underwater Penetration by 
Cavity Charges 

The object of underwater tests with shaped charges 
is to hole a steel target through an intervening layer 
of water. A direct application is to attack on sub- 
marines, where one would like to pierce the inner 
hull through the layer of liquid between the hulls. 
Another application is to the attack of capital ships 
by shaped-charge torpedo warheads, where several 
liquid-filled and air-filled bulkheads are to be per- 
forated. 

For simple experimental tests, if is convenient to 
define an underwater range or distance through water 
at which a given charge will perforate steel plate of 
a given thickness in 50 per cent of the trials. The 
Explosives Besearch Laboratory undertook an exten- 
sive investigation of 1%-in. diameter shaped charges, 
using generally y 2 -in. mild steel plate hut also other 
thicknesses as the target.*’’^ The Eastern Laboratory 
of the du Pont Company under contract with Divi- 
sion 8 undertook a scaling law investigation with 
steel cones in 3-in. and 6-in. diameter charges, using 
y^-in. plate.®^ The general discussion that follows is 
based mainly upon those two investigations. 

Explosive Filling and CHAPtOE Length 

The effect of charge length upon the underwater 
range is about the same as upon steel target penetra- 
tion in air. Maximum range is attained by a length of 
about 3.0 charge diameters. At 2.4 diameters, the 
range is within 90 per cent of the maximum. In- 
crease beyond 3.0 diameters does not increase the 
range, hut the greater charge weight will of course 
result in improved general underwater shock-wave 
effectiveness. 

The patterji of the underwater blast pressure and 
momentum about a sha])ed-charge torpedo warhead 
compared with that al)Out a conventional one has 
been investigated.®* To the sides and rear, the shaped- 
charge warhead gave peak jn-essures and momenta 
practically the same as those of the conventional 
warhead, despite the smaller charge weight. Ahead, 
these quantities for the shaped-charge warhead fell 
to minimum values, below those of the conventional 
warhead, over a zone about 22^/^° from the axis. On 
the axis itself, of course, the sha])ed charge produced 
the intense, penetrating jet, with pressure and mo- 
mentum beyond the range of the measuring instru- 


SHAPED CHARGES 


75 


meiits. Tims, the shaped-charge effect can be incor- 
porated with little loss in general effectiveness, except 
for a minor loss over the region noted. 

With the notable exception of the aluminized ex- 
plosives, the range for an underwater shaped charge 
with different explosives runs more or less parallel 
to the general blast effectiveness. Torpex, which pro- 
duces greater general underwater damage than an 
equal weight of Composition B, is not so effective in 
producing a shaped-charge effect. It appears likely 
that the energy released in the reaction of the alu- 
minum is too late to influence the motion of the 
liner leading to jet formation. Therefore Composi- 
tion B is the better filling where shaped-charge effec- 
tiveness is the primary consideration. 

Air Space 

Corresponding to stand-off in air, underwater shaped 
charges require some air space beyond the end of the 
charge for the development of maximum jet action. 
The cavity itself must, of course, be kept free of water, 
otherwise the jet action is completely destroyed. 

in a general way, optimum air space for maximum 
range varies with liner shape and liner material much 
as optimum stand-off does for steel target penetration 
in air. The optimum underwater air space is, how- 
ever, somewhat shorter than the optimum stand-off 
in air; and for steel cones at least the range continues 
constant, though individual measurements show more 
erratic behavior, at air spaces well beyond the opti- 
mum. The optimum air space is therefore in effect 
the shortest air space at which the maximum range is 
obtained consistently. 

Typical results are shown in Figure 5 for uncon- 
fined 1%-in. diameter cast rentolite charges (pro- 
tected from the water by cardboard tubes). Addi- 
tional data for 20° and 30° cones, not included in 
Figure 5, indicate that for these liners the optimum 



Figure 5. Effect of air space on range, 1 ^-inch diam- 
eter cones and charges. 


air space is zero. One notes the remarkable effect of 
increased air space on the behavior of the aluminum 
cones. Whereas the optimum air space for 45° steel 
cones is about 0.5 cone diameter, the optimum for 
45° aluminum cones is about 4.5 cone diameters. 
This behavior of course cori-esponds to the large opti- 
mum air spaces noted for aluminum cones in air. 

There is evidence for supposing that the first few 
inches of Avater provide stand-off for later parts of 
the jet as AA^ell as constituting target material for 
the front of the jet. This evidence is based on experi- 
ments in Avhich relatively thin layers of water AA^ere 
backed by thick steel targets and the depths of pene- 
tration in the steel observed for different thicknesses 
of Avater. 

Liner Thickness and Shape 

The optimum liner thickness for unconfined charges 
appears to be slightly greater than for steel target 
penetration in air, about 2 per cent of the diameter 
for 45° steel cones. The difference may be due to the 
mild confinement offered by the Avater itself. For 
charges confined in steel, the optimum thickness is 
greater, as observed in the case of steel target pene- 
tration in air. For confined charges, cone wall thick- 
nesses not far from those found best for confined 
charges in air AA^ould be satisfactory. At any rate, the 
liner thickness does not affect the range critically. 
The optimum cone weight is nearly independent of 
cone angle in the range 45 to 120° ; in other Avords, 
the optimum i hid' ness is proportional to the sine of 
half the apex angle. For cones more acute than 45° 
the optimum Aveight appears to be greater. 

Figure 6 shoAvs the range for various cone angles 
at 0.5 charge diameter and at optimum air space, 
using steel cones. The charges Avere unconfined cast 
Bentolite. The ranges Avould be improA^ed about 10 
per cent by using Composition B. One sees that at 



Figure 6 . Range versus cone angle, steel cones, 1^- 
inch diameter Pentolite charges. 


{ToxFiiiWiiAr 


76 


EXPERIMENTAL STUDIES OF EXPLOSIVE PHENOMENA 


0.5 charge diameter air space, 45° cones give the 
greatest range, 11 charge diameters for 0.31 charge 
diameter mild steel plate. At zero air space, 30° 
cones would be best, but the maximnm range would 
be inferior to that of 45° cones at 0.5 charge diameter 
air space. With nnlimited air space (3.5 charge diam- 
eters), 60° cones give the greatest range, about 
12.5 charge diameters. As a matter of fact, an even 
slightly better range may be olhained using 45° ahi- 
minnm cones at 4.5 charge diameters air space. Alu- 
minum cones appear to be relatively better nnder 
water than in air. Since limitations of space in prac- 
tical underwater weapons make large air spaces im- 
practical, 0.5 charge diameter using 45° steel or 
copper cones appears to be the best condition to aim 
for. Copper shows superiority over steel similar to that 
observed in steel target penetration in air. The range 
of a 45° copper cone at 0.5 charge diameter air space 
is about 30 per cent greater than for a steel cone. 

The adverse effect of a flat base flange covered by 
explosive has been observed in underwater penetra- 
tion as in air. Confined charges should be designed 
with the cone base the full diameter of the charge at 
the place where it is installed. 

Underwater Scaling Laws 


from a steel cone (less in defeating the jet from an 
aluminum cone). For large thicknesses of water, 
however, the depth in the steel tails off more gradu- 
ally, so that 10 or 12 in. of water in this range may 
be the equivalent of only 1 in. of steel. 

G eneral Applications 

The most immediate general applications of the 
underwater shaped-charge effect are to antisubmarine 
bombs and to torpedo warheads. These developments 
are described in Chapter 3. 

Linear cutting charges appear to be rather ineffec- 
tive under water. The depth of the cut, at best 0.8 
charge width in mild steel, falls off rapidly with in- 
creasing thickness of water between the charge and 
target. Two charge widths of water will almost com- 
pletely dissipate the cutting effect of the best linear 
charge. 

4.3.4 Theory of Jet Formation and 
Target Penetration 

Mechanism of Jet Formation 

The nature of cone collapse and jet formation has 
been made clear through exploitation of the flash 
radiographic technique by J. C. Clark and L. B. 
Seely at the Ballistic Research Laboratory in this 
country and independently by J. L. Tuck in Great 
Britain.^^*®^ Flash radiographs of V 2 to 1 microsecond 
duration have shown the various stages leading to 
formation of the jet and have given some idea of its 
dimensions. For %-m. diameter 45° steel cones, for 
example, the jet diameter is the order of only 1 mm. 
Hemispherical liners have been shown to behave dif- 
ferently, turning inside out instead of collapsing like 
acute cones. The spreading of the jet under the 
influence of high-speed rotation has also been shown. 

Confirming evidence has been obtained from ex- 
plosive flash photography.®®*®^ Interpretation of these 
pictures was at first obscured by the presence of an 
opaque shock wave surrounding the jet in air or in 
propane when the latter was used to quench lumi- 
nosity. When the jet was photographed in a vacuum, 
however, pictures similar to those obtained by the 
flash radiographic technique resulted. 

In the light of the flash radiographic evidence, a 
theory of jet formation was developed independently 
by G. Birkhoff in this country and hy J. L. Tuck and 
G. I. Taylor in Great Britain. By drawing an 
analogy with jet development from converging sheets 
of liquid (representing the cone surface under pres- 
sure far above the yield strength), equations were 


The underwater shaped-charge effect appears to 
scale linearly, that is, if one increases the charge 
dimensions in a fixed proportion, including diameter, 
length, liner thickness, and air space, and also the 
thickness of the steel target, the distance through 
water at which 50 per cent perforations are obtained 
increases also in the same proportion. A puzzling ex- 
ception has been noted with small-scale charges 
against quite thin steel plate. Using 1%-in. charges 
and Vs-in. mild steel plate, all cone angles between 
45 and 100° gave practically identical performances 
at 0.5 charge diameter air space. This finding was not 
in agreement with results for 3-in. diameter charges 
against ^/i-in. plate. 

One cannot assign a definite water equivalent of 
steel as target material for the shaped-charge jet. 
This is not surprising since the latter parts of the 
jet that have lower velocity than the forward part 
may penetrate through appreciable thicknesses of 
water and yet create pressures in steel well below the 
yield point. If one plots depth in steel versus thick- 
ness of water penetrated, for moderate thicknesses of 
water (great enough to ovei’come the stand-off effect 
previously mentioned) 1 in. of water is equivalent to 
slightly more than 0.5 in. of steel in defeating the jet 


[r(7M'll)K.VTU T?;| 


SHAPED CHARGES 


77 


deduced, based on hydrodynamic principles, relating 
the masses going into the high-velocity jet and the 
slug-like residue to the angle at which the walls meet, 
directly observed in flash radiographs of early stages 
of liner collapse. 

Mass in jet sin“ ^ 

- = , 1 
Mass in slug 2 

where /3 is the half-angle included between the walls. 
This /3 is not the same as the original cone half-angle 
a but is related to it through the ratio of the velocity 
with which the liner is projected from the explosive 
cavity wall to the detonation velocity of the explosive. 

Velocity of projection sin {/3 — a ) 

^ • ( 2 ) 

Velocity of detonation cos a 

Equations were derived also for the relative jet and 
slug velocities. 

If one attempts to deduce the mass in the jet 
merely by subtracting the total slug mass from the 
total mass of the original cone, one will be in error; 
since at a late stage in cone collapse, at least with un- 
confined charges having the same diameter as the cone 
base, the slug pinches off from the skirt of the cone, 
leaving an appreciable amount of the latter to frag- 
ment into relatively coarse, slow-moving pieces that 
probably have little penetrating power. Interesting 
experiments to show this process were conducted at 
the Explosives Research Laboratory using explosive 
charges of reduced power.^® Several techniques were 
devised for measuring the true contributions of mass 
to the jet from various parts of the cone, of which 
the simplest is to fire presectioned cones into a tank 
of water, recovering and weighing the slug seg- 
ments.'^^’'^® These measurements turned out to be con- 
sistent with equation (1), at least for the apex halves 
of the cones, in that values of (3 were deduced that 
agreed reasonably well with the values observed by 
flash radiography, taking into account the difference 
in the scale of the charges. For a 1%-in. diameter 
45° steel cone of 0.037-in. wall thickness in an un- 
confined charge, about 50 per cent of the cone’s mass 
goes into the slug and about 20 per cent into the 
high-velocity jet. 

The lower halves of the cones, according to the slug 
recovery technique, show a rapidly increasing ratio 
of mass in the jet to mass in the slug as one ap- 
proaches the region at which the slug pinches off. 
It is difficult to reconcile this increase with the ideal 
hydrodynamic process represented by equations (1) 
and (2). The flash radiographs show, however, that 


material continues to be pulled from the base of the 
slug for some time after collapse is complete. Birkhoff 
has termed this the secondary phase of jet formation 
but has attributed it to squirting from within the 
slug because of the hydrostatic pressure acting on it. 
Birkhoff’s mechanism for this effect seems improb- 
able because the pressure is certainly not any greater 
than that driving the liner together in the first place. 
It appears possible instead that the slug, under enor- 
mous hydrostatic pressure, is pulled out by tension 
resulting from continuation of the same inertial 
forces that lead to separation of the jet from the slug 
originally. The appearance of the slug during late 
stages of jet formation is strongly reminiscent of 
Bridgman’s metal specimens that have been strained 
by tension while under a hydrostatic pressure of 
25,000 kilograms per square centimeter.'^*^’'^^ This 
speculation is interesting because the greater ductility 
of copper would then give rise to a greater quantity 
of material drawn into the latter part of the jet 
during this secondary phase of jet formation, thereby 
accounting plausibly for the superiority of copper 
over steel as a cavity charge liner material. 

A weakness of the Tuck-Taylor-Birkhoff ideal hy- 
drodynamic mechanism is that it fails to account 
directly for the well-established velocity gradient 
that exists in the jet. It can be made to do so by an 
assumption concerning the distribution of velocity 
with which the liner is projected,"^® but one would 
then like to have a theoretical treatment of this proc- 
ess. It is possible, on the other hand, that the so-called 
secondary phase of jet formation contributes more 
heavily to the overall performance than has been 
generally recognized. At any rate, the primary hy- 
drodynamic mechanism is essentially correct for de- 
velopment of the leading part of the jet, coming from 
the apex half of the cone. It represents the major 
theoretical advance to date in the treatment of cavity 
charge phenomena. 

Theory of Target Penetration by 
Shaped-Charge Jets 

A theory of target penetration was presented in an 
early report from the Explosives Research Labora- 
tory.'^® The theory of jet formation also advanced in 
that report was shown subsequently by the flash radio- 
graphic evidence to be wrong, but the theory of target 
penetration, based to a considerable extent upon op- 
tical observations of jet velocities and penetration 
velocities appears to be essentially correct. 

One assumes that since the pressures developed in 


{f oxFTj aMxiArx^ 


78 


EXPERIMENTAL STUDIES OF EXPLOSIVE PHENOMENA 


the target by jet action are in general far above the 
yield strengths of common target materials, includ- 
ing steel, the resistance to penetration may be cal- 
cnlated approximately in the same way as one cal- 
cnlates the resistance encountered by a fragment in 
passing through a fluid. The resulting equation for 
the velocity of penetration takes the form : 


Case I 


2 m 


nv-u) 

dA' 

( 'ase 1 r 

_ 

1 ni 


nv-u) 

d A ’ 

Case TTl 


1 in 


(v-uy 

d A 


where U is the penetration velocity, the jet velocity, 
in the mass per nnit length of the jet, A the jet cross- 
sectional area, and d the target density, depending on 
the motion of the jet particles after striking the tar- 
get. Case I corresponds to elastic impact, the jet 
particles recoiling with the same momentnm they 
had originally but reversed in direction (a more re- 
fined treatment would take account of the forward 
motion of the impact surface). Case IT corresponds 
to the situation in which forward momentnm of the 
jet particles is annihilated, the particles moving to 
the side. Case TTT corresponds to the situation in which 
the jet particles are slowed down to the same forward 
velocity that is acquired by the target material. It is 
not possible in the present state of onr knowledge to 
tell which situation or which cross between situations 
actually exists during target penetration by shaped- 
charge jets. For immediate practical considerations, 
however, the differences are of less importance than 
the general form, which suggests that the penetration 
velocity should depend only on the target density 
and not on its strength. This was confirmed by op- 
tical determinations of penetration velocities through 
various materials ranging from water through lead. 
The depth of penetration also, to a first approxima- 
tion, should depend for a given charge oidy on the 
inertia of the target, but the hole diameter on the 
other hand should depend on interaction between the 
rate of penetration and the strength of the target. 
It was pointed out, however, that when the process 
of so-called primary penetration was over and the jet 
all consumed, the material in the target would have 
some forward momentum. Iflastic flow would there- 
fore continue until the forces were reduced to about 
the elastic limit. This process, referred to as second- 


ary penetration, would have the effect of deepening 
the hole somewhat, to an extent depending on the 
target’s strength. These ideas were confirmed l)y direct 
experimental evidence. Thus, while the depth of pene- 
tration by the 1%-in. diameter M9A1 cone charge 
(47)°^ 0.037-in. wall steel cone) in an all-lead target 
is ahont (S in. com])ared with 5.40 in. in an all-steel 
target, the overall depth in a target consisting of 
2 in. or 4 in. of lead backed by steel to reduce sec- 
ondary penetration to the same level encountered in 
the all-steel target is actually less (5.37 in. and 4.81 
in. respectively for 2 in. and 4 in. of lead) than in 
the all-steel target, showing the greater resistance to 
primary penetration by the denser lead medium.^*^^ 
Similar experiments going in the opposite direction 
were made with aluminum targets. At the same time, 
the hole diameter in lead is many times larger than 
the diameter in steel. The shape of the hole thus has 
no direct connection with the shape of the jet. One 
may actually fire the jet through a small hole (larger, 
of course, than the true jet diameter) in a steel plate 
without enlarging the hole, though the hole that 
would be produced by the jet in passing through a 
similar nnholed plate may be consideral)ly larger.®^ 
The jet was assumed to consist of a train of in- 
dependently moving particles covering a certain effec- 
tive cross-sectional area A about the axis but with a 
negative velocity gradient from the tip to the rear. 
Tins was shown hy velocity measurements determined 
optically after the jet had passed through various 
thicknesses of steel. The leading velocity of the jet 
emerging fi’om a given thickness of target decreases 
with increasing target thickness and is furthermore 
consistent with the supposition that the particular 
part of the jet involved had been traveling uniformly 
with that velocity all the way from the charge. Later 
parts of the jet therefore do no work on the forward 
part of the target, which is opened up independently 
by preceding parts of the jet. The effect of stand-off 
was explained as due to the lengthening of the jet 
(decrease in the term ni of case III) resulting from 
the velocity gradient with increasing distance from 
the charge. At extremely short stand-offs, the jet is in 
a sense inefficient in penetrating the target; momen- 
tnm is delivered at a rate too fast for the target to 
be pushed out of the way. Under this condition, more 
of the jet is consumed in the forward part of the 
target than is necessary and this inefficiency is re- 
flected ill the greater entry diameter of the hole pro- 
duced and also in a slower rate of penetration. As the 
stand-off is increased, the jet becomes more efficient 


SHAPED CHARGES 


79 


ill that the decrease in penetration per unit length of 
jet is more tlian compensated for liy the increased 
length of the jet. If this were the only consideration, 
one might expect the depth of penetration to go on 
increasing with increased stand-off (the hole diam- 
eters at the same time decreasing) until the jet den- 
sity hecame so attenuated by lengthening that the 
rate at which momentum was delivered per unit cross- 
sectional area (the stagnation pressure) approached 
the yield strength of the target. Since, however, differ- 
ent segments of actual jets are never perfectly coaxial, 
the jet has a tendency to spread (one sees indications 
of this in flash radiographs) or increase in effective 
cross-sectional area with increasing distance from the 
charge. This spreading makes the jet less effective, 
and, eventually, the spreading becomes more impor- 
tant than lengthening, so the depth of penetration 
passes through a maximum at a stand-off of the order 
of several charge diameters. At larger stand-offs, the 
average depth of penetration decreases but at the same 
time becomes more erratic, so that an occasional 
charge, presumably more perfectly aligned than ordi- 
narily, will show an exceptionally good penetration, 
comparing favorably with the average obtained at the 
shorter so-called optimum stand-off. 

Ify assuming a “reasonable” value for the ratio 
vi/A (e.g., 1 to 2 g per cubic centimeter for the M9A1 
jet at moderate stand-off), one may arrive, by select- 
ing one of cases T to IIT, at calculated values for the 
rates of ])enetration through various target materials 
in quite good agreement with the observed values. For 
a more quantitative treatment, however, detailed in- 
formation concerning the jet structure is needed, in 
particular the cross-sectional area and linear mass 
distribution of the jet. Some effort to determine the 
latter quantity was made through jet momentum and 
kinetic energy measurements,®^ but the interpretation 
of these quantities is uncertain due to the fact that 
unknown quantities of momentum and energy are lost 
through material blown out of the hole. The total 
momentum and kinetic energy of the 1%-in. diameter 
;M9A1 cone charge appear to be about 3.8X10*’ g per 
centimeter per second and 10,400 calories respectively, 
hut the way in which these quantities are distributed 
among the various parts of the jet is not easily de- 
termined. The jet diameter could, in principle, be de- 
termined by flash radiography but the resolution is 
at present not fine enough for the measurements to be 
other than rough estimates of the order of magnitude. 
In the absence of experimental methods for determin- 
ing accurately these two essential properties of the jet, 


efforts to develop a quantitative theory of target pene- 
tration were abandoned though the present qualita- 
tive theory appears to account in a simple way for 
the various penetration phenomena that have been 
observed. 

Jet Velocities and Penetration Velocities 

Shaped-charge jet velocities and penetration veloc- 
ities through various target materials have been meas- 
ured with the rotating drum camera. The leading vel- 
ocity for the jet (actually the velocity of the lumi- 
nous shock wave created in air by the jet) from a 
]%-in. diameter 45° steel cone is of the order of 7,500 
mps using a Pentolite or a Composition B charge. 
The velocity decreases with increasing liner mass and 
appears to be independent of the particular metal 
constituting the liner. For given liner mass, it de- 
creases also with increasing cone apex angle. The 
velocity is atonishingly persistent in air, remaining 
practically constant out to at least 10 charge diam- 
eters from the charge. 

As mentioned previously, the jet velocity shows a 
negative gradient from the tip to the rear, shown by 
determining the leading velocity after penetrating 
through various thicknesses of target. The following 
approximate values are representative for 1%-in. 
diameter M9A1 cone charges at 6-in. stand-off. 


Thickness of Steel 
Penetrated (in.) 

0 

1 

2 

3 


Leading Velocity Emerging 
from the Target (m/sec) 
7,700 
6,400 
4,800 
3,300 


This cone will penetrate normally through about 
5 in. of mild steel. The slowest part of the jet con- 
sists of the slug, which for the M9A1 cone (25 g 
without flange) weighs about 13 g and probably has 
a velocity of about 400 mps. The slug velocity 
cannot be measured by optical methods hut it may 
he inferred from flash radiography. The slug evidently 
contributes nothing to the penetrating power of the 
jet, but it is considered to be a formidable secondary 
projectile in its own right if it can get through the 
hole in the target. 

The penetration velocity for a given jet, as men- 
tioned previously, is a function of the target density. 
For the 1%-in. diameter M9A1 cone at stand-offs not 
less than the optimum for depth of penetration, the 
average rate of penetration through the first inch or 
two of mild steel is’ about 2,500 mps. 


/('(j.\i'ii>i:\'ri TfTi 


80 


EXPERIMENTAL STUDIES OF EXPLOSIVE PHENOMENA 


Shaped Detoxatiox Waves 
There has naturally been much speculation whether 
the cavity effect can be improved by tailoring the 
shape of the detonation wave to fit the liner more 
perfectly. The first concrete suggestion for accom- 
plishing such an adjustment in wave shape appears 
to have been made by H. J. Poole in Great Britain.®'"^ 
He proposed using a core of low-velocity explosive sur- 
rounded by a shell of high-velocity explosive, adjust- 
ing the shape of the boundary between them to obtain 
any desired wave shape. By using a simple cylindrical 
core and shell, a cone-shaped wave may he produced in 
the core. With a cast TNT core and a cast Pentolite 
shell, improvement of the order of 15 per cent over 
straight Pentolite was actually obtained with a num- 
ber of types of small-scale cavity charges both in steel 
target penetration in air and in underwater range. 
The effect proved to be rather temperamental when 
applied in certain actual weapons,^® though in no case 
was the performance inferior to that of an all-Pento- 
lite charge. Improvement was observed also using an 
inert wooden core in a Pentolite surround, terminat- 
ing the core a short distance above the cone apex so 
that the cone would be completely covered by explo- 
sive. In this case, the wave shape was modified pre- 
sumably by peripheral initiation of the explosive near 
the cone. A further improvement in performance, 
additive to that produced by the core, was observed 
on relieving the confinement towards the base of the 
charge. The reason for this effect is not known, but 
charges were prepared haviiig l)oth TNT cores and 
relieved confinement that gave depths of penetration 
as much as 30 per cent above normal. 

Further experiments have been made using Baratol 
cores and Composition B surrounds.®® The greater 
difference in detonation rates permits one to modify 
the wave shape more drastically. Improvement over 
straight Composition B was actually observed, but 
the advantage was rather small. The low power of 
Baratol no doubt neutralizes most of the advantage 
obtained from shaping the detonation wave. We need 
for this purpose a high-powered explosive having a low 
detonation rate. Many interesting phenomena were 
observed in the Baratol-cored charges through which 
an acute cone-shaped detonation wave was propagated. 
Under certain conditions, an intense Mach wave ap- 
peared in the center of the core that resulted in amaz- 
ingly deep central pits when the flat-ended charges 
were fired resting on steel plates in the standard plate- 
denting brisance test. Belated studies of Mach effects 
in air are described in an early report.®® 


4.3.5 Fuzing of Shaped-Charge Weapons 

The fuzing of shaped-charge projectiles at moder- 
ate to high striking velocities raises a problem because 
of the requirement of preserving stand-off. At low 
striking velocity, such as the 270 fps attained by the 
M6A3 2.36-in. HEAT rocket, fuzing may be success- 
fully accomplished by means of a sensitive base- 
detonating fuze, though even here one must be careful. 
At higher velocities, the problem is more difficult to 
solve with a base fuze. The early T20 models of the 
57-mm HEAT shell at 1,200 fps were giving no pene- 
tration at all, the shell crushing all the way back until 
the main charge was initiated by impact before the 
T9-I base-detonating fuze functioned. The M67 105- 
mm HEAT shell equipped with the standard M62 BD 
fuze has been shown by high-speed photography at the 
Ballistic Besearch Laboratory to be firing at little 
better than zero stand-off, the ogive crushing almost 
through its entire length before deceleration is suffi- 
cient to activate the fuze. In this case, the loss in 
stand-off does no particular injury to the performance, 
which is impaired more seriously by the spin of the 
shell. 

One may reduce fuze delay to a minimum by using 
a point-initiating fuze. Such a fuze has the advantage 
that the functioning time is a property of the fuze 
and not of deceleration of the entire projectile. For 
shaped-charge applications, one requires a fast method 
of transferring the initiating impulse from the nose 
to the base, since it is essential for the development 
of the cavity effect that the main charge be initiated 
from the end opposite the cavity. At the same time 
one must avoid as much as possible introducing mate- 
rial on the axis of the charge in the path of the main 
jet. Within the cavity, any obstacle whatever close 
to the axis will destroy the cavity effect almost com- 
pletely. Even ahead of the cavity, however, an obstacle 
such as a long firing pin, common in many types of 
point-initiating fuzes, will serve as so much added 
thickness of target material. The fact that the pin is 
slender makes little difference because as seen from 
flash radiographic evidence, the jet is even finer, and 
to the jet, the pin therefore presents an obstacle as 
formidable as a plate of metal as deep as the pin is 
long. 

Shaped-Charge Spit-Back Fuze 

With these considerations in mind. Division 8 ap- 
plied considerable energy to developing the principles 
of point-initiation of shaped-charge projectiles by 
means of a miniature shaped-charge element in the 




SHAPED CHARGES 


81 


nose wliieli would fire back down an axial flash-tube to a 
tetryl booster at the base of the projectile.®® This re- 
search led to the development by Picatinny Arsenal 
of the service fuze, PI, AI90, standard in the M307 
57 mm HEAT shell. This fuze bears a one-piece so 
called auxiliary detonator cup made of aluminum 
having a re-entrant O.Ol-l-in. wall 80° cone in the 
base. The diameter is % in. and the unit is loaded 
with 2.1 g of pressed 50/50 Pentolite. To eliminate 
the need for a tiring pin, the fuze is initiated by means 
of a percussion-sensitive detonator in the nose, flash- 
inff down a short hollow tube to the main detonator 
housed in the arming rotor. This method of initiation, 
however, is not sensitive to ground impact. The Brit- 
ish No. 233 fuze is based on similar principles. 

The miniature shaped-charge element develops a 
jet with a velocity of the order of 7,000 m per second. 
There is negligible delay (of the order of 1 micro- 
second) in the initiation of tetryl eight inches or more 
away when struck by the jet. The estimated overall 
functioning time of this type of fuze in a small pro- 
jectile, the size of the 57-mni shell, is about 50 micro- 
seconds. The presence of the axial flash tube running 
back through the main charge does not impair the 
depth of penetration in any way. In fact, with hemi- 
spherical steel liners, the depth of penetration is re- 
markably improved by the presence of the tube, for 
reasons that are by no means clear. There is, however, 
a reduction in hole diameter over the first caliber or 
so of penetration in steel plate that is associated with 
the presence of the tube. For this reason, the spit-back 
principle cannot l)e readily applied where a large-hole 
entry diameter is essential, such as in small follow- 
through projectiles. 

A fairly successful shaped-charge rocket fuze, T- 
2000, for nonspinning rounds, was developed, though 
never adopted for Service use, by minor modifications 
of the Service plastic-bodied M52B1 trench mortar 
fuze. The conventional booster cup Avas replaced by 
the miniature shaped-charge unit and the firing pin 
was replaced hy a plastic adapter holding one of the 
percussion detonators used in the MOO fuze. The 
M52B1 body was not ideal for the purpose, Imt it did 
contain approved setback arming elements. The orig- 
inal 114-in. metal firing pin, if retained to ensure 
functioning on ground impact, seriously impaired the 
depth of penetration, as expected. Some experimental 
work was done in collaboration with xVllegany Bal- 
listics Laboratory on a plastic firing pin for tbis fuze, 
wbich seemed to be suitable if it could be made to 
function on ground impact as well as against plate. 


for the 2.36-in. high-velocity rocket grenade, T59. 
The results Avere not particularly encouraging because 
of mechanical AA^eaknesses of the pins, but a successful 
fuze could no doubt be developed by folloAving up this 
line of investigation. The loAV-density plastic offers con- 
siderably less resistance to the jet than does a metal pin. 

The shaped-charge spit-back method of initiation 
has also been applied to the fuzing of experimental 
1,000-lb shaped-charge bombs fired statically. The 
unit Avas 1 in. in diameter and fired doAvn a 2-in. 
ID flash tube to initiate the booster about 48 in. 
aAvay. The Service AN-M103 bomb nose fuze Avas 
adapted for the purpose simply by substituting the 
spit-back element in place of the conventional booster 
cup, but a less inassiA^e body and firing pin Avould be 
better suited to the purpose. 

Electkomagnetic Impact Fuze 

An electric impulse may be generated on impact by 
driving a magnet in the nose through a surrounding 
coil. This impulse is easily led by Avires to an electric 
detonator at the base of the projectile. The German 
fuze, Z66, is based on this principle, though not ap- 
plied to shaped-charge rounds. Division 8 at the re- 
quest of NDRC Division 3 participated in designing 
and testing a shaped-charge head for the high-veloc- 
ity T59 2.36-in. rocket fuzed Avith an electromagnetic 
impact fuze, T2003, to be deA^eloped by the Bell Tele- 
phone Laboratories under contract Avith Division 3. 

The original AA^ork on this method of initiation for 
shaped-charge projectiles Avas carried on by the Erank- 
ford Arsenal (Fuze T16E1). The Bell Telephone Lab- 
oratories added engineering refinements to make the 
unit suitable for production and assembly in large 
quantities. 

The magnet in the nose is a holloAV cylinder, pro- 
viding a hole 0.70 in. in diameter for the jet to shoot 
through. This leaves the entire axial region ahead of 
the main charge clear of obstructions. The wires are 
led back through crimps in the edge of the cone base. 
To ensure functioning on ground impact, a secondary 
relatively sIoav inertia-activated detonator mechanism 
is located in the base, on the theory that against plate 
the electrically activated detonator Avill function first. 

Preliminary tests of the complete round, Avhich has 
a velocity of about 385 fps, gave inferior results that 
Avere traced to the presence of excess sealing com- 
pound on the cone around the regions Avhere the Avires 
passed through. Subsequent tests Avith the sealing 
compound removed gave excellent results. The depths 
of penetration at normal incidence exceeded 8-in. in 


(Tux I'l 


82 


EXPERIMENTAL STUDIES OF EXPLOSIVE PHENOMENA 


homogeneous armor using 2.118-in. diameter 45° 
copper cones. This performance was equivalent to 
that produced by static charges fired at 3-in. stand-off 
in the entire absence of the fuze mechanisms in the 
noses. The projectiles performed satisfactorily also at 
30° and even at 45° incidence. The indicated fuze 
functioning time was about 60 microseconds, repre- 
senting an ogive collapse of less than V 2 in. before 
detonation. 


This development was unfortunately started too 
late to be of any use during the war. The principle 
is however of considerable value, since it may be read- 
ily adapted to weapons of other sizes, including also 
certain nonshaped-charge projectiles where there is an 
advantage in a fast point-initiating base-detonating 
fuze system.^ 

^The complete project is described in a joint Division 3, 
Division 8, and Bell Telephone Laboratories Report.*'^ 


(I ii\ ri iTi:vri vi.\ 


Chapter 5 


THE THEORY OF THE DETONATION PROCESS^ 


T he wokk done by various Division 8 contractors 
greatly strengthened the evidence for the validity 
of the thennodynamic-hydrodynamic theory of the 
propagation of one-dimensional detonation waves 
through solid as well as gaseous explosives. This 
theory, which originated with Eankine, Hugoniot, 
Chapman, and Jouguet, is based on the assumption 
that at the point where detonation takes place there 
is conservation of matter and energy and that the 
equation of motion of mechanics applies there. These 
three almost self-evident assumptions must be supple- 
mented by one additional condition about which there 
has been a great deal of dispute and discussion, that 
the detonation velocity will be the minimum permitted 
by the above conditions. In order to apply these simple 
principles to any actual case, it is necessary to have 
information about the equation of state of the prod- 
ucts of the explosion as well as a knowledge of the 
energy as a function of pressure and volume. 

The work under Division 8 involved an extension of 
previous efforts to apply these equations because more 
elaborate equations of state were employed and the 
question of the effect of shifting chemical equilibria 
was explored. The overall results were sufficiently suc- 
cessful, i.e., they agreed sufficiently well with experi- 
mental measurements of the detonation velocities of 
a wide variety of solid explosives over a range of load- 
ing densities, so that considerable confidence in the 
soundness of the basic theory now exists. The signifi- 
cance of this result from a practical viewpoint is that 
it permits the calculation of the detonation velocities 
of hitherto unmeasured explosives if the chemical 
composition and the heat of combustion of the mate- 
rial is known. Furthermore, it shows quite conclusively 
that the detonation velocity is not a mysterious quan- 
tity to be endowed with undue significance, since the 
theory clearly relates it to the thermochemical prop- 
erties of the detonation products. 

A by-product of these investigations is an estimate 
of the pressure, temperature, and density of the prod- 
ucts of detonation immediately behind the detonation 
front within a solid explosive. These estimates have 
proved very useful in later work in which the prop- 

*This section is based on a summary prepared by S. R. 
Brinkley, Jr. 


erties of shock waves in air and water from high ex- 
plosives were calculated. 

The equation of state which seemed to work the 
best, although designed for a higher pressure region, 
was not in conflict with that successfully used by 
others for the lower pressure region involved in pro- 
pellent powders. 

The work summarized in the preceding paragraphs 
began with the preparation of a review of the litera- 
ture of the past sixty years on hydrodynamic and 
thermodynamic theory as applied to detonation and 
shock waves.'’ Since this review was never issued as 
a report but was instead circulated in mimeographed 
form to the group directly interested, its contents are 
described in some detail in the paragraphs immedi- 
ately following. 

The review begins with a qualitative discussion of 
the building up of a discontinuous shock front. Then 
the Riemann formulation of the equations of hydro- 
dynamics is introduced.^ These equations constitute 
a statement of the equations of motion and continuity, 
and, for the plane case with adiabatic flow, they may 
be written 



where / is the time, ./• the (Filler) coordinate of dis- 
tance, u the particle velocity, p the density, and p 
the pressure; c is the velocity of small amplitude 
sound waves. The Riemann function w, defined by 

«(?) = ('’ Idp, ( 2 ) 

J P(P0) ^ 

may be increased by an arbitrary constant. Since the 

^This literature survey by G. B. Kistiakowsky and E. B. 
Wilson, Jr., is referred to in subsequent reports as Hydro- 
dynamic Theory of Detonation. Part I. A Literature Survey. 
The succeeding parts of the report on Hydrodynamic Theory of 
Detonation have been issued. 


i^yFlbKVTl.\£l> 


83 


84 


THE THEORY OF THE DETONATION PROCESS 


pressure and density are connected by the adiabatic 
law, the Eiemann function may be considered a func- 
tion of either the pressure or the density. From the 
equations (1) it is evident that r is constant along 
lines, called characteristics, in the x-t plane such that 

^=M + C (r lines), (3) 

and that s is constant along lines in the s-t plane 
such that 

^ — u — c (alines). (4) 

dt 

The lines have the following useful properties. 

1. There is a line of each type through each point 
in the x-t plane. 

2. If the values of s and r on the lines passing 
through a given point are known (as, for example, 
the generating surface) then u and w are known there. 
Then p and p can be found from equation (2). 

3. If lines of a given kind having different values 
of r (or s) meet in a point, there is a discontinuity 
in u,p at that point. 

4. If in a given region s has the same value along 
adjacent s lines, the r lines are straight in that region. 

5. Similarly, if r has the same value along adjacent 
r lines in a given region, the s lines are straight in 
that region. 

6. For a perfect gas, at least, the curvature of an r 
or an s line is positive if u increases along the line. 

In the report under review, the properties enumer- 
ated are employed in a discussion of the building up 
of the discontinuous shock or detonation front. 

A shock wave is produced by the acceleration of 
some generating surface. A detonation wave is self- 
maintained through the energy received from the 
chemical reaction of the explosive. 

The equations for the conservation of mass, mo- 
mentum, and total energy have been employed by 
Rankine^ and Hugoniot^ in the formulation of three 
conditions relating the pressure specific volume 
v^, and particle velocity of the medium behind the 
moving discontinuity to the velocity I) of the discon- 
tinuity and the pressure Pi, specific volume and 
particle velocity of the undisturbed medium in 
advance of the discontinuity. 

(5) 

«2 = «1 + V(Pj — Pi) — 

— -El = i(P2 + Pi)(i’i — Vi) , 

where E 2 — Ei is the difference in specific energy con- 


tent of the material behind the front and the undis- 
turbed medium in advance of it. This quantity can 
be calculated by the thermodynamic relation 





dv, (6) 


where Q is the heat (absorbed) of reaction at con- 
stant volume per M grams of reactant at the initial 
temperature Tj, and (7„* is the constant volume heat 
capacity of M grams of products, gaseous products 
being considered in the ideal gas state the tem- 
perature of the detonation front, is related to p^, and 
t ’2 by an equation of state 

p = f{T,v). (7) 

In the case of shock waves, where there is no chemical 
reaction, equation (6) may be employed with § = 0. 
The first of equations (5), together with equations 
(6) and (7), defines a curve in the for 

specified values of p^ and With an additional re- 
lation between p^ and v^, these quantities may be de- 
termined, and the detonation velocity and particle 
velocity behind the detonation front are determined 
by the first two of equations (5). 

Chapman^ and Jouguet® postulated that the detona- 
tion velocity is the minimum velocity compatible with 
the other conditions, it then being given by 


D = C2, 

B = + ( 8 ) 



Arguments in support of this hypothesis are given in 
the reports under review and by Becker® and Scorah."^ 
However, no existing demonstration of the validity 
of this hypothesis is without theoretical objections, 
and equation (8) is employed with ad hoc justification 
of its success in interpreting explosion phenomena, 
particularly in the case of gaseous explosions where 
there is no uncertainty as to the form of the equation 
of state. 

If a suitable form for the equation of state (7) 
exists and if the composition of the products of the 
explosion reaction is known or can be determined, 
simultaneous solution of equations (5) to (8) per- 
mits the determination of the detonation velocity and 
of the pressure, specific volume, and temperature of 
the detonation front. Lewis and Friauf® have com- 
pared experimental values of the detonation velocities 


roNFiDEyflAn 


THE THEORY OF THE DETONATION PROCESS 


85 


for the explosion of oxygen-hydrogen mixtures, botli 
with and without tlie addition of a third, inert gas, 
with the predictions of theory, employing the ideal 
gas equation of state. When account Avas taken of 
dissociative equilibria of the product gases, good agree- 
ment between theory and experiment Avas obtained. 

A study of the calculation of detonation A^elocities 
for solid explosives has been made by Schmidt.® These 
calculations are subject to three criticisms. The 
Abel equation of state, 

— =nm\ (9) 

was employed, in Avhich the covolume h is assumed to 
be a constant and 11 is the gas constant for M grams 
of gas. Using observed detonation Axdocities for the 
evaluation of h, it Avas found experimentally that h 
depended significantly on the density of the gases, 
a fact AAdiich Avas not taken into account in the deriva- 
tion of the theoretical equations for the acoustical and 
detonation A^elocities. The analysis of the explosion 
products in bombs at Ioav density Avas used for the 
calculation of the composition of the detonation prod- 
ucts, a procedure of questionable validity, because it 
is very likely that the several gaseous equilibria in- 
volved are frozen because of too sIoav reaction rates at 
uncertain and variable stages of the expansion. Finally 
a less general energy equation than (6) Avas employed. 

The sui’A^ey of the literature AAdiich has just been 
revieAA^ed AA^as folloAv^ed by a report on the calculation 
of the velocity of detonation of solid explosives.^® For 
this purpose a modification of the semiempirical equa- 
tion of state of Becker Avas used. This equation of 
state has been sIioaaui to reproduce satisfactorily 
Bridgman’s data for the behavior of nitrogen at room 
temperature and at densities as high as 1.2 g per cc. 
Omitting Ioav temperature terms and adopting a T~^ 
dependence of the covolume on temperature, the 
equation of state Avas Avritten 

rvM^nUT{l + 2'e^), 

^ miv ’ 

Avhere A:/TMs equivalent to the vander Waalscovolume 
in the limit of low densities. The composition of the 
explosion products Avas approximated by the rule that 
in listing the products oxygen is considered to react 
first Avith carbon to form carbon monoxide, additional 
oxygen reacts Avith hydrogen to form Avater, and the 
remaining oxygen, if any, reacts with carbon monox- 
ide Avith the formation of carbon dioxide. It Avas 


shoAvn that the calculated detonation velocity of the 
usual organic explosives is insensiti\"e to the com])o- 
sition of products, and the results of rough equilib- 
rium calculations justifying the neglect of dissocia- 
tive equilibria Avere presented. Experimental values of 
the detonation velocity Avere employed to calculate 
the covolume constant h for a series of explosives. 
The resulting A^alues of li shoAved an oA^rall depend- 
ence on density of 15 to 20%, an effect too great to 
be attributed to differences in composition of the ex- 
plosion products at high and Ioav loading densities. 

The final rej^ort^^ of the series under consideration 
continues the development of methods for the calcu- 
lation of A^elocities of detonation of solid explosives 
and contains a discussion of plane shock Avaves in air 
and Avater and a description of rarefaction and reflec- 
tion phenomena.^ 

The more general equation of state, 
pvj\l = nliTi^X -|- 

k ( 11 ) 

miv 

Avas employed, in Avhich the coefficient /S Avas included 
in the exponential term to secure constancy of the 
coAolume constant k AAuth respect to density of the 
gases, and in Avhich a dependence of the covolume 
upon temperature Avas adopted. By trial, the value 0.3 
Avas adopted for the parameter The rule for the 
composition of the products of explosion Avhicli Avas 
previously proposed Avas employed. A computational 
procedure Avas devised in Avhich 'ffdeal” values of the 
detonation velocity and temperature Avere calculated 
on the assumption that the product gases obeyed the 
ideal gas laAv. The correction factors resulting from 
the introduction of the equation of state (11) for the 
real gases could then be tabulated as functions of the 
heat capacity of the product gases, considered ideal, 
and the argument. 


Avhere is the density of the intact explosive. The 
published tables contain a systematic numerical error 
Avhich, although to some extent self-compensating, 
largely invalidates the values of the covolume con- 
stants evaluated by the use of experimental values 
of the detonation A^elocity. It should be noted that 

®This reference contains all the purely theoretical material 
of the earlier reports by the same authors. In particular, it 
supersedes the discussion of plane shock waves in air and 
water presented by them in reference 12. 


fSx JUDEXTULl 


86 


THE THEORY OF THE DETONATION PROCESS 


the edition of the tal)le8 ein))loyed in tlie evaluation 
of [i did not eontain the systematic error. 

The report concludes with a discussion of shock 
and rarefaction waves based upon the liiemann formu- 
lation of the equation of hydrodynamics. The llay- 
leigld^ solution of the Riemann equations for a simple 
progressive wave is given. In this case, the Riemann s 
is constant over a region and the r lines are therefore 
straight. Then 

u = f[x— (w + c)l], (13) 

where / is an arbitrary function determined by the 
boundary conditions at the generating surface and the 
Rankine-Hugoniot conditions, equations (5), which 
are supernumerary boundary conditions which must 
be satisfied at the shock front. 

Rarefaction waves are considered, and it is shown 
that in the case of rarefaction no discontinuity can 
occur. A qualitative description of the profile of a 
plane detonation wave is given, and it is shown that 
the detonation wave is followed by an advancing 
rarefaction wave. Tables of the peak values of the 
temperature, pressure, density, and shock wave veloc- 
ity as functions of the peak value of the particle veloc- 
ity for shock waves in air and water are presented. 
These are constructed with the aid of the Rankine- 
Hugoniot conditions, equations (5), and in the case 
of air, the values were taken from a report by Bethc 
and Teller.i"*^^ 

Following a discussion of reflection phenomena at 
boundaries, a method is developed for the calculation 
of the initial shock wave velocity for a shock wave 
initiated by a plane detonation wave. It is shown that 
the Rieniann r must be constant across the boundary 
between explosion products and exterior medium. 
This constant becomes half of the particle velocity 
of the explosion products immediately behind the det- 
onation front if the Riemann w function for the 
exterior medium is defined as 

ylp^ ( 11 ) 

where is the density of the gases behind the det- 
onation front. Then 

Us = — io + u.,, (15) 

where is the initial particle velocity in the exterior 
medium and u.^ is the particle velocity behind the 
detonation front. Since w may be considered a func- 
tion of p only, the initial shock pressure may be de- 
termined and the initial shock velocity follows from 
the Rankine-Hugoniot equations (5). A sample cal- 


cnlalion is given for sliock waves in air, employing the 
equation of state (11) for the explosion products and 
the ideal gas adiabatic equation of state for air. Nu- 
merical results are given for l^FTN and Tetryl, each 
at two loading densities. The calculated values of the 
initial shock wave velocity are in good agreement with 
experiment. 

An extension of the procedure for calculating the 
velocities of detonation of solid explosives to include 
those explosives which yield solid carbon as a reaction 
product has been accomplished by the assumptions 
that the volumes of solid and gas are additive, that 
the gas obeys the equation of state (11), and that the 
solid has zero coefiicients of thermal expansion and 
basic compression.^'’ The composition of the reaction 
products is assumed to be that for chemical equilil)- 
rium at the temperature and pressure immediately 
behind the detonation wave, and a numerical proce- 
dure, involving successive approximations, is developed 
for the determination of this composition from a 
consideration of the simultaneous equilibria in- 
volved. On the basis of an assumed composition, a 
value of the “ideaF’ temperature is found on the 
assumption that product gases are ideal. The correc- 
tion factor and the quantity defined by 


A- 




( 16 ) 


(/'s and 7/ are the specific volume and weight frac- 
tion res})ectively of solid C) are tabniated as functions 
of the ratio of the heat ca])acities of the explosion 
products, gases being considered ideal, and the argu- 
ment. 


PiA- 




(17) 


ddie specific volume of the explosion products behijid 
the detonation front is determined hy equation (16), 
and the pressure is then determined by the equation of 
state, ddiese values of the state variables are then em- 
])loyed in a determination of the equilibrium comi)()si- 
tion of the explosion products by ordinary thermody- 
namic methods. The resulting composition is employed 
in a new determination of the pressure, temperature, 
and specific volume behind the detonation front, and 
the cyclical computational process is continued until 
successive approximations to the composition and the 
state variables are identical to some desired degree of 
precision. An ‘‘ideal” value of the detonation velocity 
71* is then found on the assumption that product gases 
are ideal, and the correction factor J)/D* is obtained 


ox n HK.vi'i.vi.] 


THE THEORY OF THE DETONATION PROCESS 


87 


Troiii a tabli* of Iho (juaiitity as a rmu'lioii oL' ilie ar^u- 
iiK'iits y* and .i\. The i)artiele velocity may then he 
evaluated rroin the second of the Hankine-ll ugoniot 
conditions, equations (5). 

As a (‘onseqnence of the determinations of the com- 
position at eqiiilihriiim of the products of the explo- 
sion reaction, it is shown that a good approximation to 
tlie conq)osition is afforded hy the following conven- 
tional scheme. In listing the products of the reaction, 
it is assumed that oxygen reacts first with hydrogen 
with the quantitative formation of water, the remaining 
oxygen reacts with carhon to form carhon monoxide, 
and additional oxygen, if any, reacts with carhon 
monoxide to form carhon dioxide. The conventional 
decomposition scheme suggested hy Kistiakowsky and 
Wilson resulted from a consideration of the water- 
gas equilihrinm in which the effect of the nonideality 
of the gases was not included. The effect of gas imper- 
fections is to reverse this equilihrinm completely, thus 
giving rise to the conventional decomposition scheme 
outlined above. The detonation velocity is insensitive 
to the composition of the explosion products, and cal- 
culations based n])on the conventional decomposition 
scheme differ little from the much more elal)orate 
calculations which include the determination of the 
equilihrinm composition. 

The covolnme constants were determined from ex- 
})erimental values of the detonation velocities of se- 
lected ex})losives hy an extensive series of successive 
ap{)roximations which are outlined in the report under 
review. The final values of the constants for the in- 
dividual gas species are closely proportional to the 
high temperature values of the van der Waals h as 
evaluated hy Hirschfelder, AlcClnre, and Curtissd^ 

The computational methods described in reference 
16 have been applied to the calculation of velocity of 
detonation, and temperature, density, and pressure 
of the detonation wave front for sixteen organic ex- 
plosives.^® Comparisons of the calculated velocities of 
detonation with experimental values were possible 
with twelve of the explosives. Agreement was satis- 
factory for seven of the explosives; with five of the 
explosives the calculated values were lower than the 
experimental values. These five explosives have high 
detonation rates and relatively high oxygen contents. 

In some as yet unpublished Avork at the Explosives 
Research Laboratory^® a simplified calculation of the 
velocities of detonation of solid organic explosives has 
led to better agreement Avith experimental values than 
have the more elaborate calculations just described. 
In the simplified calculation the equation of state 


(11), Avith a single covolnme constajit })er unit mass 
of gaseous explosion i)iodnct, Avas employed. The con- 
ventional decomposition scheme, suggested lyy Brink- 
ley and Wilson, Avhich leads to quantitative formation 
of Avater, Avas employed to estimate the composition 
of the i)roducts. The covolume constant Avas evaluated 
by use of experimental values of the detonation ve- 
locity of oxygen-rich explosives. The specific volume 
of solid carhon Avas treated as an adjustable para- 
meter and its value Avas determined hy the use of ex- 
perimental values of the detonation velocity of oxygen 
deficient explosives, ddie best fit betAveen theory and 
experiment is obtained Avith a covolume constant of 
12.7 })e]- gram of gaseous product and Avith a value 
of 0.840 cc per gram for the specific volume of carbon. 
With these parameters, calculated and observed det- 
onation velocities are in good agreement, i.e., .better 
than 6^. The agreement Avould have been consider- 
ably improved, if nitroguanidine, an explosive Avith 
exceptionally Ioav detonation temperature, had been 
giAen less Aveight in the least squaring process em- 
ployed for the determination of the covolume con- 
stant. 

By 1046, the best experimental values of the det- 
onation velocity had become someAvhat different from 
the earlier values employed by Boggs and Martin, 
and this AA'Ould result in a someAvhat different value 
of the coA^olume constant. A small residual variation 
in the covolume cojistant Avith_ density of explosive 
suggests that the parameter of the equation of state 
(11) should be re-evaluated. It is felt that the use 
of a T“3 dependence of the covolume on tempera- 
ture, Avhich Avould necessitate the re-evaluation of 
both the covolnme constant and Avonld improve 
the agreement betAveen theory and experiment for 
cold explosives Avithout sacrificing the excellent agree- 
ment obtained by Boggs and Martin for the explo- 
sives Avith higher detonation temperatures. 

Calculations of detonation pressures have been 
made and are presented in references 20 and 21. 

Til the former report the pressure inside aerial 
hombs at the instant of explosion has been calculated 
for several fillings, namely. Composition B, 50/50 
Amatol, 60/10 Amatol, 50/50 Amatex, 60/40 Ama- 
tex, and TNT at certain initial densities reported as 
used in practice. Conqiosition B gaA’e about 20^ 
higher values than Amatol and Amatex, Avhich Avere 
nearly the same, A\4iile the TNT Avas about 15% loAver 
than the Amatol-Amatex group. The TNT result 
Avould have been someAvhat higher if its density had 
been nearer the others. 


£I)Xi-il.>KXTIArji 


88 


THE THEORY OF THE DETONATION PROCESS 


Tlic above results, as well as the initial tempera- 
ture, density, eomposition, and the ealeulated detona- 
tion veloeity, were obtained from the hydrodynamic- 
thermodynamic theory previously described^’^ and 
represent values right behind the detonation wave 
front. The same order applies to the values obtained 
on the assumption of an adiabatic constant volume 
explosion. An outline of both calculations is included. 
In the one the quantities calculated are those which 
occur just behind the detonation front as it travels 
down the length of the bomb. In the other, it is as- 
sumed that the pressure throughout the bomb has 
been equalized without loss of energy or expansion. 

In the latter report the pressure immediately be- 
hind the detonation wave front, the detonation ve- 
locity, and the pressure of adiabatic constant volume 
explosion have been calculated for several service ex- 
plosives at loading densities reported to be employed 
in aerial bombs. An estimate has been obtained of the 
maximum available work of each explosive. The calcu- 
lations of the properties of the adiabatic constant 
volume explosion state assume that the pressure is 
equalized throughout the bomb without loss of energy 
or expansion. 

Composition B gives significantly higher values of 


each of the above quantities than Ednatol, Amatol, 
Aniatex, and TNT. The order of the other explosives 
is dependent on the loading density of the different 
fillings. When compared at the same loading density 
in terms of adiabatic constant volume explosion pres- 
sure or of the maximum available work, the order is 
Ednatol, 00/40 Aniatex, 50/50 Aniatex, TNT, 50/50 
Amatol, 60/40 Amatol. This order may be changed 
by a variation of a few hundredths in the loading 
density. The loading density seems to be more impor- 
tant than the type of filling with the Amatols, Ama- 
texes, and TNT, as far as the adiabatic constant vol- 
ume explosion state is concerned. 

It is further shown that surrounds of TNT equal 
to 7'% of the total explosive have a negligible elfect 
on the adiabatic constant volume explosion pressure 
of 50/50 Amatol or 50/50 Aniatex. 

In addition to the work described in the preceding 
pages, Division 8*^ also supported investigations of 
related problems : the theory of detonation waves^^ and 
a theoretical study of the initiation and propagation 
of detonation waves.“^’^^ 

‘^The final report on this work as a Division 8 project and 
the report on its continuation as a direct project of the Bureau 
of Ordnance make up a BuOrd report which has not been 
issued as of the closing date of this summary. 


f^>M-ll>KNTlAU 


(Chapter 6 


PROPELLANTS 


T he work ox rijorEi.EAXTS in Division 8 did not 
got under way until sonictime later than the work 
on liigh explosives, and at the termination of the ac- 
tivities of the Division a larger part of its eftort was 
being spent on propellants than on high explosives. 
One large portion of the work on propellants can be 
outlined in the following terms. Donble-base powder 
has excellent mechanical properties and is smokeless. 
It has, however, two serious dithcnlties in terms of 
the requirements of modern war. The ballistic prop- 
erties vary considerably with change in temperature, 
and it is not possible by solvent or solventless extru- 
sion to prepare grains of large diameter, for example, 
8 inches or more. Division 8 undertook to develop 
propellants which wonld not be subject to these two 
handicaps. Molded composite propellant ((1.2) con- 
sists of a fuel (ammoninm picrate) and an oxidant 
(alkali nitrate) held together by a resinous hinder. 
A composite propellant can be made in grains of 
large diameter and its ballistic properties vary only 
slightly with the ambient temperature; it produces 
large amounts of smoke on burning, (hist perchlorate 
propellant (G.4) is a material which can be poured 
into a mold and cured in place. It too offers the pos- 
sibility of })reparing very large grains and it too 
})roduces smoke on burning. Solvent extruded com- 
posite propellants (G.d) consist of a double-base 
matrix and a tiller which is a mixture of fuel and 
oxidant. Their ballistic })roi)erties are quite consistent 
over a considerable temperature range ; hut because of 
the filler they produce smoke and, like other double- 
base powders, there is a limit to the grain size. The 
most promising single development in this general 
direction was that of cast double-base })owder: grains 
of double-base ])owder are treated with an explosive 
solvent; on warming, the grains swell and coalesce 
to a single large grain the size and shape of the mold. 
AVhen this casting process is combined wdth the use 
of small amounts of solvent-extruded composite pro- 
pellant to govern the burning rate, one has, as a 
result, a powder which combines the desirable fea- 
tures of double base and the composites. 

In 'connection with the propellants described in 
the preceding paragraph theoretical studies Avere 
made of the mechanism of burning of propellants 
(6.1), and experimental studies of the design and 


construction of nozzles for use in motors burning 
these propellants (6.6). 

dun propellants, rather than rocket propellants, 
formed the subject of other lines of investigation. 
Flashless powder for Xavy guns was developed in 
which the nitroglycerin of the Ihltish Cordite N 
formula Avas replaced l)y the ex})losive plasticizer 
DINA. By incorporating BDX and a deterrent in 
nitrocellulose, a start Avas made on the development 
of poAvder for small arms and cannon Avhich Avould 
either have the same potential as current poAvder hut 
be less erosive or Avould have higher potential than 
curreJit poAvder and be no more erosive. 

A large program of ex})eri mental Avork on double- 
base powder Avas also carried on. This included sta- 
bility and suiweillance measurements and studies of 
methods of measurement. Methods of analysis of 
])OAvder Avere devcloi)cd and studies Avere made of the 
physical properties of double-base jwAvders as a func- 
tion of their composition. These studies Avill be found 
described in detail in Sections 6.9 through 6. Id. 

6 1 THE THEORY OF THE BURNING 
OF ROCKET POWDERS'^ 

Introduction 

With the develo})ment of composite propellants 
(see Sections 6.2 and 6.6) it became desirable to make 
a theoretical study of the burning of these propellants 
in order to gain a better understanding of the reasons 
for their desirable ballistic properties and, ultimately, 
to be able to improve them. Before starting this study, 
hoAvever, it Avas necessary to develop someAvhat fur- 
ther the theory of the burning of double-base })oav- 
ders, and actually the main part of this summary Avill 
deal Avith this topic. A section at the end Avill take iq) 
the composite propellants. The theory is based very 
largely on the experimental work of Dr. B. L. CraAV- 
foid, Jr., and his associates at the University of Min- 
nesota. Not only have they performed a beautiful 
series of experiments, both on double-base and com- 
posite propellants, Init they have also made many 
suggestions regarding the theory. The preliminary 

“This section is taken from a summary prepared by O. K. 
Rice. 


HlXTrTDfA-TTTlT^ 


89 


90 


PROPELLANTS 


ealciilatioiis on tlie tlieory liavc boon presented in a 
series of interim re})orts. Except for the last/’ these 
contain some errorsd'*^ The final results are given in 
references 7 and S, which also contain more complete 
lists of references than are given here to the work of 
Crawford and othei’s. 

6.1.2 Theory of Burning of Double-Base 
Powders 

Theories heretofore proposed for the hiirning of 
propellants may he divided into two general classes. 
The first assumes that heat developed in the reacting 
gas beyond the surface of the powder is conducted 
hack to that surface, thus alfecting the rate of reac- 
tion at the surface, which is assumed to play an im- 
portant role in determining the rate of burning. The 
second assumes that the rate of burning is deter- 
mined solely by the reactions in the gas phase, con- 
duction of heat back to the surface playing only a 
secondary role. The first type of theory is the main 
theme of the present summary, but the second, which 
has been developed by Boys and Corner,^ has also 
been considered to some extent ; in particular, a proof, 
which involves no integration of the differential equa- 
tion, has been given of Boys and Corner’s proposition 
that the slope of the curve, logarithm of the rate of 
burning against logarithm of the pressure (the pres- 
sure coefficient, an important quantity ballistically), 
is equal to half the order of the gas-phase reaction 
under the particular assumptions of their theory. 

The burning of the powder appears to occur in 
three stages, all with evolution of heat. The first stage 
occurs at the surface of, or within, the solid powder 
and results in the formation of unsaturated fragments 
which are ejected into the gas phase normal to the 
surface. In the second stage, these fragments react 
in the gas phase in an assumed second-order reaction. 
These two stages together constitute the fizz burn- 
ing; the gases produced are still capable of further 
reaction. At low pressures (from one to a few atmos- 
})heres) the only heat reaching the surface is that 
produced by the reaction at the surface, which is 
thus self-sustaining at a definite (limiting low-pres- 
sui-e) rate. (At still lower pressures the rate drops 
again ; this phenomenon is not treated in this sum- 
mary.) At higher pressures heat generated from the 
gas-])hase reaction can reach the surface and the reac- 
tion rate then increases with pressure. 

The thii'd stage of the reaction consists of the 
flame, which appears only at pressures exceeding 20 
atmospheres, and apparently does not affect the rate 


of read ion mdil the pressure reaches about 100 at- 
mospheres. The flame reaction is assumed to be of 
the nature of a branching-chain explosion; this is 
sup})orted hy its appearance. It is sup]X)sed that after 
the gases leave the fizz zone there is built up a small 
concentration of active particles, this occurring in 
the dark zone which is observed between the surface 
of the powder and the flame. When these active i)ar- 
ticles reach a sufficient (but still exceedingly small) 
concentration an explosion occurs, which lasts through 
a small but definite zone at the base of the flame. 

This picture of the burning process is summarized 
and the notation established in Figure 1. 



OO TIMES - 1 0 ti tg tj 

To /room) TEMPERATURES T T^ T, T, T, 

-^^TEMP j 

To LOWEST POSSIBLE T ' T ' T, 

TEMPERATURES (WHEN NO 
HEAT FLOWS BACK) 

THERMAL DIFFUSIVITIES->t 

MOLECULAR WEIGHTS "W W* W^ 

Figure 1. Schematic sketch of a stick of burning powder. 


T 



When a steady state is established, the total amount 
of heat Avhich crosses any cross section of the powder 
or the reacting gas (the sum of that carried by con- 
duction and that carried by mass motion) must be 
the same for all cross sections. This ‘datv of steady 
heat fioAv,” which is of fundamental importance in 
the theory, was established by Boys and Corner and 
independently by J. E. Mayer in uiqiublished work. 


Tuansfkr of Heat to the Solid Surface in 
Fizz Burning 


C^oming to the details, Ave first consider the fizz 
l)urning process, neglecting the effect of the flame. 
Applying the hiAv of steady heat fioAv to the problem 
of conduction of heat from the exothermically react- 
ing gas back to the surface, but assuming that all 
the reaction in the gas takes place in a single plane 
at a\, there may be derived a fundamental relation- 
ship, Avhich connects the pressure p, the burning 
rate M, and the temperature of the surface : 


Avhere 


p = - 






T, — T's 


•(1) 

( 3 ) 


iCO,\hMT)KNTTAj } 


THE THEORY OF THE BURNING OF ROCKET POWDERS 


91 


M can be expressed in the form of an Arrhenius 
ccpiation, 

:\j = , (3) 

where A is a ^^frequency factor’’ and Eg the energy of 
activation of the reaction that takes place at the sur- 
face of tlie solid. Since fi, Kg, 7’/, 7^, Eg, and 
d are to be considered as parameters, values of 
which are to be preassigned, and can be elimi- 
nated from these equations, to give M as a function 
of p, obtaining a curve which can be compared with 
experiment. The equations can be easily generalized 
to take care of the fact that the reaction in the gas 
takes place over a finite zone instead of in a single 
plane. This effectively simply replaces equation (2) 
by another relation. 

In eliminating Tg and from the equations, it is 
assumed that fi is given hy 


Effect of the Flame on the Burning Process 

This is important at higher pressures, above about 
100 atmospheres. It is first necessary to consider the 
nature of the branching-chain reaction and to attempt 
to correlate it with the measurements on the length 
of the dark zone as a function of pressure made hy 
Crawford and his collaborators. We assume that the 
flame starts when certain active constituents, which 
are formed in the gas starting from the end of the 
fizz zone, reach a certain critical concentration. The 
rate at which these active particles are formed will 
depend on the pressure (but not, at least greatly, on 
the temperature), and the critical concentration may 
also depend on the pressure. If we let be the con- 
centration of active particles, we have 


where is a rate constant independent of the tem- 
perature; that is, the activation energy of the gas- 
phase reaction is negligibly small. If this reaction 
had a high activation energ}', ti, the time required 
before reaction occurs after the fragments leave the 
surface, would not depend primarily on a rate of 
reaction, but on how long it takes the gas to move out 
to a point where it is hot enough to react, and the 
theory would revert to the Boys-Corner type, which 
makes the slope of the log M versus log p curve equal 
to just half the order of the gas-i)hase reaction. If this 
energy of activation is low, is the time of reaction 
after the fragments leave the surface, the theory de- 
veloped in this summary will apply, and other factors 
as well as the order of reaction will affect the slope of 
the curve. Certain characteristics of the burning rate 
versus pressure curve and related effects offer evidence 
to show that the latter alternative is correct. 

If we are interested only in the burning rate at 
moderately low pressures, the above equations are all 
that are needed. Temperature and pressure coeffi- 
cients for the fizz burning region are readily derived. 
The pressure coefficient turns out to be largely deter- 
mined by the ratio il///il//, where il// is the value 
of M at the temperature T^' attained by the gaseous 
products of fizz burning if there is no flame, and 
is the value of M at the lowest possible (low-pres- 
sure) value Tg of Tg. Under these circumstances, of 
course, 7\ = T/; otherwise T^ is determined by the 
flame. 


where is a rate constant and the order of the 
reaction. If the critical concentration of is of the 
form where B and m are constants, then the 

time (after the time C) necessary for the develop- 
ment of the critical concentration and, hence, for 
the flame to start, is 


^2 ^1 


B 




( 6 ) 


The distance — a\, which is essentially the length 
of the dark zone, since can he shown to be 

given by 

K1\M 


P 




where 


K = 


BB 

W,k, * 


(U 

(8) 


To get agreement with the earlier measurements of 
Crawford, Iluggett, and Parr'®^ one would set m + 
rig “h 1 = d.5, but later experiments^®*^ indicate a 
larger value; we have taken, in later work, 5.5. 

For this dark zone we get an equation analogous 
to equation ( 1 ) : 


where 


il/7?7’, / ^2 — /, 

1 V \^2 V 


(S’) 




( 10 ) 


Finally, we have to consider the reaction taking 
place in the finite reaction zone {x 2 to x^) in the 
flame. It is this zone in which the heat of the flame 


EcTHFiDivyriALg 


92 


PROPELLANTS 


reaction is actually generated, only a small concen- 
tration of active particles being built up in the dark 
zone. Also we must suppose, in order to get any agree- 
ment with the rate-pressure curve, that the reaction 
zone in the flame does not have nearly so high a 
dependence on pressure as the dark zone, so that the 
reaction zone actually is much longer than the dark 
zone at sufficiently high pressures. We assume, in 
fact that 


/. — = 




( 11 ) 


where is a constant. We can write another equation 
analogous to equation (1) : 


where 


Mm\ — 


( 12 ) 


(13) 


To take care of the finite reaction zone, we would 
again replace equation (13) by another relation. 

It is now possil)le, if the parameters are known, 
to handle equations (1) to (4) with equations (6) to 
(13) simultaneously, eliminating unnecessary quan- 
tities and obtaining a relation between M and p which 
will hold into the pressure region above 100 atmos- 
pheres. 


Equation of the Pauameteus 

Before the equations of the preceding sections can 
he applied, various parameters must be determined. 
Estimates of the important quantities for a typical 
double-hase powder (HES 4016) are herewith tabu- 
lated. 


Tj = 770 K /Cj = 0.6/p, cmVsec, (p in at.) at 770 K 

Ti = 1100 K /Cl = 2.8/p, cmVsec, (p in at.) at 1100 K 

Ti = 3000 K ic = 49 at.^-^cm'^sec/g deg if m + n 2 -j- 1 = 3.5 

Wg = 57g/mole k = 9.\10‘‘ at.®-® cm®sec/g deg if m -j- n 2 + 1 = 5.5 

IFi = 27g/mole E, = 17,300 cal per mole reaction 


Mostly these are based on data obtained by Crawford 
and his collaborators, but P' is a guess limited by 
the fact that an o])aque double-base powder shows no 
red glow while fizz burning, and T[ — T'^ is obtained 
fiom the experimental temperature coefficient. This 
temperature difference is important in the theory, and 
is rather definitely fixed by the temperature coeffi- 
cient. Eg depends upon T[ and 7"' and on M[ and 
4/'. The latter are in turn so chosen as to best fit the 
burning rate data, as are and A-g. These quantities 
are not given here, but Aq will be discussed below. 


The Buuning Pate-Phessuke Cuuve 

The experimental curve for log M versus log p shows, 
in general, a flat region or at least one of small slope 
at low pressures. This corresponds to the region where 
Tg is close to In the higher pressure range, where 
heat is getting back to the surface from the gas phase, 
the slope of the log 4/ versus log/) curve rises gradually, 
eventually approaching about 0.7. This general trend 
is very well reproduced by tbe theory. 

In some types of powder, the curve tends to flatten 
out again at pressures aroiuid 100 atmospheres, to be 
followed by a rather noticeable rise where M begins 
to go np because heat from the flame reaction begins 
to reach the powder in appreciable quantities (S- 
shaped curves). In the usual type of double-base pow- 
der, such as HES 4016, there is no such marked effect 
of tbe flame, but a pretty good idea of the pressure 
at Avhich the flame begins to be effective may be ob- 
tained by comparison with a similar powder in which 
catalyzed nitrocellulose Avas used.^°® With this poAV- 
der the flame is much closer to the surface than Avith 
ordinary HES 4016, and the rate of burning is higher 
at high pressures hut about the same at Ioav pressures. 
To get the effect of the flame to come in at a suffi- 
ciently loAV pressure it appeared necessary, if in -\- 
+ 1 = 3.5, to assume that Kj Avas actually about 
20 times as large as that tabulated above. HoAATver, 
later it Avas found that Avith ni -f- 1 = 5.5 and 

the flame consequently approaching the surface much 
more rapidly, the discrepancy aatis reduced to 4- or 
5-fold, and it Avas concluded that this Avas Avithin the 
limits of eri‘or. 

Effect of Coolants 

The effects of added coolants, such as centralite 
and paraformaldehyde,^®^ on the parameters can be 
estimated. Since these coolants can be assumed to be 
either inert ingredients which do not take part in the 
reaction (centralite) or substances AAdiich actually de- 
compose and absorb heat in the solid phase (para- 
formaldehyde), tbe effect is to lower Tg, 7\' and 
Beasonably good, though not absolutely accurate, pre- 
dictiojis of tbe effect of tbe coolants can be made. 
Especially interesting is the case of a 20% para- 
formaldehyde poAvder. The predicted curve shoAvs a 
very Ioav rate in the fizz burning region, Avith a A^ery 
steep rise Avhere the flame comes in. Actually, the 
])OAvder Avill not burji in the Ioav jiressure fizz burning 
region, but the points at higher pressures fall near 
tbe curve in tbe region where the flame has a pre- 


F(WFii>K:wi.\id 


THE THEORY OF THE BURNING OF ROCKET POWDERS 


93 


dominating effect. Other types of coolant exist, which 
cool the ffaine and produce the S-sliaped curves noted 
above. 

Kkactiox Times and Distances and 

T II El R I NTERPRETATION 

A question arises as to whether the solid-phase 
reaction actually occurs at the surface, or whether it 
takes place in a finite region within the solid. In 
favor of the first hypothesis are the facts (1) that the 
value of A corresponding to the estimated values of 
d// and Ms' is close to what one might expect from a 
unimolecular decomposition of the exposed NO3 
groups, and (2) that microscopic examination of the 
surface of powder which has been burned and 
quenched shows an altered layer, which, if the quench- 
ing occurred at 150 psi, is about equal to the thick- 
ness which one might expect to be heated by conduc- 
tion.^^ In favor of the second hypothesis are the facts 
( 1 ) that if the quenching occurs at atmospheric pres- 
sure the altered layer is much larger than expected,^ - 
and (2) that the altered layer is full of bubbles.^'^^ 
It seems certain that there is a reaction within the 
solid, but it may not be important except at low 
pressures. 

The value of Aq which must be used to get agree- 
ment with the burning-rate data is only about 
1.7 X 10“^’ times as great as would be the case if the 
gas-phase reaction took place at every collision of 
the reactive fragments. However, there is undoubt- 
edly a small, rather than actually zero, activation 
energv, which accounts for this factor in part. 

It may be noted that the length of the fizz zone 
can be calculated, though there are no experimental 
data for comparison. Some values of this length, aq, 
at various pressures, are as follows: 

p (at.) 1.66 7.3 29. 160. 

.aq ifx) 334 35 5.2 0.63 

Relationship avith Other Work and Suggestions 
EOR Xew Work on Dourle-Base Poavders 

In the theory considered above, nothing Avas said 
in explanation of the rather sharp falling off of the 
rate at very Ioav pressures (beloAv 1 atmosphere). A 
start on a theory of this effect has been made by 
OraAvford and Parr.^®^ 

The theory considered here assumes that the ac- 
tivation energy of the gas-phase reaction is Ioav, 
though the possilffe errors caused by the assumption 
have been discussed a little. The A\wk of Boys and 
Porner assumes it is high. A start at Avorking out 


the intermediate case has been made by Parr (refer- 
ence lOg and private communications). 

Shortly after this theory was developed in the BP 
reports, an essentially equivalent theory, though dif- 
fering greatly in mathematical details, Avas Avorked 
out by Eyring and his co-AVorkers^^'^^ for the fizz 
burning. Their application, hoAvever, contained an 
error. They did not consider the effect of the flame 
on the burning rate but did consider the possible 
effect on the flame of the diffusion to the side. In this 
Avay they attempted to explain the dependence of the 
dark-zone length on pressure, assuming an ordinary 
second-order reaction in the flame. In these calcula- 
tions, hoAvever, they apparently overlooked the de- 
pendence of the diffusion constant on pressure, and, 
in any event, the experiments at the Univ^ersity of 
Minnesota indicated that diffusion is probably not 
important except at rather Ioav pressures. 

One of the chief desiderata in the further study of 
double-base poAvders is some more accurate Avay of 
estimating the temperature of the surface of the burn- 
ing powder. The method used by Daniels, of incor- 
porating in the poAAMer substances Avhich melt or de- 
compose at definite temperatures, is not nnequivocal, 
for one reason because the particles of the substance 
may stick out into the gas and be heated there. Pos- 
sibly, use of a larger variety of smaller particles 
AA^ould be helpful. Other methods^’’ haA’e also been 
used but do not give unequivocal results. 

At the present stage of our knoAvledgc of double- 
base poAvders, it seems that detailed examination of 
poAvders Avith special properties, e.g., the paraformal- 
dehyde poAvders, along the lines so AA^ell outlined by 
Ch’aAvford and his associates Avould be helpful. For 
example, further burning rate data on various inter- 
mediate compositions of paraformaldehyde poAvder, 
examination of the burned surface, analysis of prod- 
ucts, heat of explosion data at various pressures, dark 
zone data, and the effect of using catalyzed nitrocel- 
lulose in such a poAvder, Avould be interesting and 
theoretically significant. 

6.1.3 Theory of the Burning of 

Composite Propellants 

Use of the principles laid doAvn above and the very 
excellent experimental Avork at the University of Min- 
nesota (references lOh and lOi and various private 
communications and memoranda) have made it pos- 
sible to attempt some speculations on the burning of 
composite propellants, Avhich contain a filler of the 


toN'KiniHyTIALA 


94 


PROPELLANTS 


oxidizing agent potassium perchlorate and the re- 
ducing agent, carhon hlack, in a hinder of doulde- 
hase powder. The perchlorate particles are of the 
order of 7.5 /x in diameter, while the particles of car- 
hon are much smaller, around 0.03 /x. 

The theory is based upon a consideration of what 
happens to individual perchlorate particles. When a 
powder containing very little filler is burned, indivi- 
dual perchlorate particles can he seen glowing in the 
surface, and they evidently have a higher temperature 
than the rest of the powder. According to Crawford, 
Huggett, McBrady, and Hanson, only the larger 
perchlorate particles glow. Some of them give rise 
to j^lumes of flame, presumably due to reaction of 
oxygen from the particles with reducing gases and 
carhon from the surrounding powder. Of course, in 
a powder containing more filler, the plumes of flame 
are merged to give an apparently uniform flame. A 
large crystal eml)edded in douhle-hase powder also 
gives rise to a flame, and from the rate at which the 
crystal is consumed and the known rate of decomposi- 
tion of potassium perchlorate at various temperatures, 
its surface temperature can be estimated to be con- 
sidei-ahly higher than that of the surrounding powder. 

As regards the burning I’ate, the experimental facts 
are roughly as follows: At sufficiently low pressures 
the perchlorate lowers the rate of burning. There is 
fhen a very sharp rise in the burning i*ate, around 
100 psi (the higher the percentage of filler, the lower 
the pressure at which this occurs), after which the 
rate increases only moderately with pressure, so that 
in the ballistic I’egion the ]>owder shows the desirable 
low pressure coefficient. A more finely ground per- 
chlorate gives, apparently, a lower rate at low pres- 
sures and certainly a higher rate at high pressures. 

The theory which accounts for or describes these 
facts may now be outlined. At very low pressures, 
where it lowers the rate, the perchlorate is supposed 
to act as an inert ingredient. (Actually there is some 
question whether it lowers the rate as much as it 
should on this basis.) But there is a tendency for it 
to react at the surface with gases from the binder. 
At somewhat higher pi’essures this reaction may be- 
come important, causing the particles to he heated 
above the temperature of the hinder. It is possible 
that only the larger particles, which stick through 
the fizz zone, are thus heated; this would also result 
in dependence on the pressure, since the thickness of 
the fizz zone decreases sharply with the pressure. 
Having been thus heated, some of the particles emit 
sufficient oxygen so that the plumes of flame hurst 


from them. When this happens more heat is gen- 
erated, the surface is heated more strongly, and the 
effect is likely to be contagious, especially in a powder 
of high fdler content, so that more particles burst 
into flame. As the pressure increases, more and more 
particles hurst into flame; in view of the remarks 
just made, this effect is autocatalytic, so that there 
is a region around 50 to 100 psi where there is a 
sharp rise of rate with pressure. At somewhat higher 
pressures, however, where practically all of the par- 
ticles hurst into flame, this effect reaches saturation; 
only the normal tendency for the rate of burning to 
increase with pressure remains, and the rate of reac- 
tion of the gases becomes determined largely by diffu- 
sion of the oxygen and the reducing materials into 
each other. Under these circumstances increase in 
burning rate is resisted by the diffusion process, and 
the pressure index goes down below the normal values. 

The smaller the perchlorate particles the easier 
is diffusion around them, accounting for the effect 
of size in the high-pressure region. At low pressures, 
decreasing the size of the perchlorate particles may 
residt in their being more uniformly heated through- 
out their hulk. Thus a given weight of perchlorate 
woidd, if finely divided, act as a better cooling agent, 
causing the powder to burn slower. 

The carbon black, whose effect has not been dis- 
cussed so far, ])lays an important role in the com- 
bustion. H may act as a catalyst, or it may act as 
a concentrated reducing agent carried in the reducing 
gases which react with the oxygen from the per- 
chlorate. In either case, absence of carhon would he 
expected to cause partial repression of the steep rise 
of rate with pressure at 100 psi, causing this increase 
to occur instead in the ballistic region. This predic- 
tion has since been confirmed by experiment.^® 

Suggestions foe Fuether Work on 
Composite Peopellan ts 

1. The decomposition of potassium perchlorate 
should be more thoroughly studied. 

2. Controlled reaction rate experiments between 
potassium perchlorate and gases, such as are given 
off in fizz huiTiing of douhle-hase powders, might he 
of interest. 

3. A careful study of the effect on the burning rate 
of the size of the filler particles at low pressures as 
well as at high jiressures should he made. Some work 
of this nature is already under way. 

4. Some light on the effect of an inert ingredient at 
low ])ressures might he obtained by experiments using 




MOLDED COMPOSITE PROPELLANTS 


95 


a iioiireactive material such as powdered sand, vary- 
in*? the particle size and percentage of sand. 

5. Photogra})hs should be made (like those made 
hy C'rawford, Huggett, McHrady, and Hanson for 
powders dilute in filler) of powders with high filler 
content around the pressures at which the sharp rise 
in rate just begins, to see if the inflammation of per- 
chlorate particles can be detected and studied. 

6. Photographic studies should he made of pow- 
ders containing very little potassium perchlorate and 
varying amounts of carbon black. 

7. Estimates should be made of the smallest size 
of perchlorate particle which glows (compare Craw- 
ford, Huggett, ^IcBrady, and Hanson) when a dilute 
powder burns under varying ])ressure conditions, to 
see whether this size parallels the thickness of the fizz 
zone. If this is found to he the case, it might indicate 
that the particles are heated and glow only if they 
stick up into the hotter regions of the gases. 

8. Powders in which the perchlorate is replaced 
hy a solid solution of potassium perchlorate and po- 
tassium permanganate might be studied, if stability 
tests indicate that they can he used. Since these solu- 
tions decompose more readily than pure potassium 
perchlorate, some light inight thereby be thrown on 
the effect of the stability of the oxidizing agent. 

9. Some consideration should be given to the elTect 
of the size of the carbon particles. Since a large car- 
bon particle might not react completely with the 
oxygen from the ])otassium perchlorate, at least close 
to the surface, and since, with its relatively smaller 
surface it would be a ])oorer catalyst, it might be ex- 
pected that increasing the size of the carbon par- 
ticles would have the same efi'ect as decreasing tbcir 
concentration. 

6.2 MOLDED COMPOSITE PROPELLANTS*’ 

^lolded composite propellants are mixtures of finely 
divided, crystalline, self-comhustible solids, for ex- 
ample, ammonium picrate and sodium nitrate, held 
together by a resinous l)inder and formed into grains 
by compression molding. The development of these 
propellants*^ had its origin in observations made by 
British workers prior to the summer of 1941. The 
British effort, however, was directed primarily toward 
the preparation of plastic propellants, puttylike ma- 
terials which would be molded directly into rocket 

•’This section is constructed from a summary prepared by 
Louis P. Hammett and Frank A. Long. 


motors, whereas the work of Division 8 was directed 
toward the preparation of hard, mechanically strong 
grains.^ 

Molded composite propellants possess certain major 
advantages over conventional propellants.*®'^* They 
ha^'e a low value of the exponent in the burning law, 
which results in a much lower sensitivity of the pres- 
sure in a rocket motor to such influences as changes in 
burning surface, nozzle area, limited area of pas- 
sages for flow of gas, than is the case with ordinary 
double-base powders.** ddiis permits packing more 
propellant in a given space, lightens the motors be- 
cause of greater reproducibility of pressure, and com- 
pensates completely for the somewhat lower specific 
impulse. The propellant burns well at low motor pres- 
sure of from 200 to 800 psi. This also aids in light- 
ening the motors. The temperature coefficient of pres- 
sure, thrust, and l)urning time is low so that these 
quantities vary over the range from — 40 to -j-140 F 
hy a factor of 1.5 compared with 5 for hallistite and 
cordite. This is extremely important for launching 
units and missile propulsion units, for which thrust 
and burning time must be as nearly as possible in- 
dependent of temperature. For artillery rockets the 
low coefficient removes the necessity of a range cor- 
rection for temperature and contributes to lower motor 
weight and generally ^icreased efficiency of the pro- 
jectile. The powder is mechanically strong and, al- 
though it is somewhat brittle, can easily be mounted 
in a motor so that the ])owder grain is not ruptured 
by impacts that will injure the metal parts of the 
motor. The propellants are of inherently great sta- 
bility and are not altered by long storage at elevated 
temperatures. It is relatively easy to apply a coating 
to the propellant to ]) re vent the burning of a given 
surface. This permits fabrication, for example, of end- 
burning solid charges with long burning times. A 
range of propellants of widely different burning rates 
can be obtained l)y simple changes of propellant com- 
position. Thus CT-492 has a burning rate of 1.0 in. 
per second at 1,000 psi and 70 F, whereas CP-401 
has a burning rate of only 0.24 in. per second under 
the same conditions. This flexibility contributes ad- 

®The work done by Division 8 on plastic propellants differed 
from that of the British in that a thermosetting rather than a 
thermoplastic binder was used, and the binder was incor- 
porated in edge-runner mills rather than in differential rolls. 
Not enough work was done by Division 8 to develop a plastic 
propellant satisfactory in every respect, but sufficient work was 
done to show the great potentialities of this type of propellant.^* 

‘^Persons not familiar with these and other terms used in con- 
nection with rocket propellants will find an excellent introduc- 
tion to the subject in reference 22. 


':xTiAr3 


96 


PROPELLANTS 


ditional latitude in the design of propulsion units. 
Finally the propellants are exceedingly well adapted 
to production in charges of relatively large diameter. 
Under wartime conditions the fact that the major 
components, potassium nitrate and ammonium pic- 
rate, were in good supply was an additional favorable 
factor. 

The compositions and properties of several of the 
standard composite propellants are given in Table 1. 


Table 1. Composition and ballistic properties of 
molded composite propellants. 


Designation 

218B 

401 

404 

492 

Ammonium picrate 

46.7 

72 

54.0 

41 

Sodium nitrate 

46.7 

. . • 

. . • 

. . . 

Potassium nitrate 

. . . 

18 

36.0 

50 

Buramine resin* 

5.1 

. • • 

. • • 

. . . 

Santicizer 8t 

1.5 

. . • 

. . . 

• . . 

Calcium stearate 

0.4 

• . . 

• . . 

• . . 

Ethylcellulose f 

. . . 

4 

5.0 

4.5 

Aroclor 1254 § 


6 

5.0 

4.5 

I 

172 

174 

174 

165 

d 

1.80 

1.64 

1.72 

1.77 

h 

310 

285 

300 

292 

n 

0.50 

0.50 

0.45 

0.42 

•Fl,o 00 

0.70 

0.24 

0.57 

1.0 

f^l.ooo 

170 

600 

240 

155 

Temp coef 

0.005 

0.005 

0.005 

0.003 


I, the specific impulse in seconds, is givei^for a chamber pressure of 1,000 
psi, and the optimum expansion ratio for that pressure. The value under 
other conditions may be estimated from the curves in Explosives Research 
Laboratory Report OSRD-1627, July 1943, or from the California 
Institute of Technology Report CIT/JAC 2, October 23, 1942. As shown 
in OSRD-1627 and 5043, the ratio of the specific impulses of two pro- 
pellants is essentially independent of pressure and expansion ratio 
except under conditions of overexpansion. Becau.se of the greater heat 
losses with small motors, the specific impulse is affected by motor size 
and is about 9% lower for 1-ounce grains of 218B than for 4.5-lb grains^ 

d is density in g/cc. 

is the impulse per unit volume of propellant (g sec/cc). 

n is the exponent in the burning law, R = 6P”. 

Ri,ooo is the linear burning rate (in./sec) at a pressure of 1,000 psi and 
at 25 C. Rates at other pressures and temperatures may be calculated 
from the values of exponent and temperature coefficient listed. 

Xi,ooo is the ratio of burning surface to nozzle throat area (the restriction 
coefficient) at which a steady-state pressure of 1,000 psi is attained. 
Values for other pressures may be obtained from the equation 
P _ K 1 
1,000 Ki,ooo 1— « 

The temperature coefficient is the quantity 
1 (dP) _ l_ idR) 

in which K is the restriction coefficient. 

*Buramine is a butyl urea-formaldehyde resin manufactured by the 
Sharpies Solvent Company. It is employed as a 65% solution in butanol, 

fSanticizer 8 is a trademarked plasticizer made by the Monsanto Chemical 
Company. 

jThe ethylcellulose has the following properties: standard ethoxy con- 
tent; 7 cp viscosity. 

§Aroclor 1254 is a liquid chlorinated polyphenyl manufactured by the 
Monsanto Chemical Company. 


The burning rate varies considerably with composi- 
tion, but the specific impulse, discharge coefficient, 
and exponent n are almost the same for the composi- 
tions listed. The flame temperatures are not known 
precisely but that of even the ‘‘hottest” composition 
(CP-492) is probably under 2500 K. All the com- 
positions produce considerable smoke, primarily po- 
tassium or sodium carbonate. 

The general process for the production of composite 
propellants-^'-® involves the addition of suitable pro- 
portions of ammonium picrate and of potassium ni- 
trate, which has been ground to a particle size® de- 
pendent on the rate of burning desired, together with 
a 50^ solution of the resinous binder in acetone to 
a 3-ft edge-runner mill. The 55-lb batch is milled for 
three hours under careful temperature control and 
with a current of dry air passing through the mill 
to remove the acetone. At the end of milling a small 
proportion of calcium stearate or other free-flow 
agent is added. The product is a solvent-free, free- 
flowing powder. In the pilot plant, 40 batches of this 
powder are blended together to give a 2,000-lb lot. 
This powder is thermostatted to 35 C and fed to a 
compression molding press. For the production of 8.5- 
in. diameter grains, this press may be a 425-ton press 
equipped with a cylindrical mold about 24 in. long 
provided with a core rod if a perforation is desired. 
Because of friction against the walls, these molding 
powders do not give satisfactory results if the length 
of the final grain is much greater than its diameter. 
Tlie molding pressure is of the order of 14,000 psi, 
varying somewhat with the composition of the pro- 
pellant. Grains are molded to have a density of about 
96% of the theoretical fully packed density. The 
singlet grains produced are ejected from the mold, 
annealed for 48 hours at 60 C and inspected. During 
the annealing, small volume changes occur and stresses 
are relieved. The product is hard and strong with a 
compression strength of the order of 3,000 psi. The 
grain walls are very close to true cylinders and the 
ends are essentially flat and parallel. No ignition of 
the propellant during the molding process has oc- 
curred at any time during the whole development. 
Although proper control of composition, water con- 
tent, temperature conditioning, and molding cycle 
yields grains of consistently good quality, failure of 
control can result in internal cracks which may lead 
to disastrously high pressures when the powder is 

®A method of determining particle size is reported in ref- 
erence 29; this should be compared with an earlier report, 
reference 30. 


ftONFIDENTIA^ 


MOLDED COMPOSITE PROPELLANTS 


97 


burned. Fortunately, an ultrasonic transmission tech- 
nique has been developed which can he carried out as 
a routine inspection operation and which detects such 
flaws with a high degree of reliability.^^ 

Experimental work on the improvement of this 
process was actively proceeding at the termination of 
hostilities, and some of the partially tested develop- 
ments have considerable promise. Of particular in- 
terest are alternate milling methods which might both 
improve the quality and lower the cost, and modifi- 
cations in the molding procedure which might elimi- 
nate the need for expensive, high-capacity presses.^-""** 

For many purposes a grain longer than the singlet 
unit is desired and is obtained by cementing the units 
together. This is relatively easy with perforated grains 
in which the direction of the burning is radial and 
hence parallel to the cement joints. An alkyd resin 
cement. General Electric Glyptal 1201, has proven 
completely satisfactory. AVith large diameter grains, 
a YiQ-m. thick cork washer is cemented between the 
units to take up irregularities in the grain ends and 
give the assembly slight flexibility. Cork washers 
which are cemented on the ends of the assembled 
charge serve both to prevent burning on the ends, 
which results in more nearly neutral burning, and 
to cushion the mounted grain against shock. Five 
cork strips are cemented longitudinally on the out- 
side of the grain to space it from the motor wall and 
to provide shock protection. Protection against shock 
by these cork mountings is completely satisfactory. 

The cementing problem is more difficult with solid 
grains, in which the burning proceeds in an axial 
direction and must therefore traverse the cement 
joints. The cement must be a very fluid one which 
can be squeezed out to give a very thin yet continuous 
layer, and then hardened by heat or chemical action. 
The grain ends must be very flat to obtain a satis- 
factorily thin cement layer. With 8y2-in. grains, flat 
ends have been obtained by machining them in an 
ordinary metal-working lathe. A suitable cement is 
General Electric Permafil 2851. The results obtained 
when it is used with machined grains are satisfac- 
torily reliable. Cementing problems and techniques 
have l)een described in detail. 

To give end burning, a solid charge of this sort must 
be ^Testricted’’ to prevent burning except on one end 
surface.^^ This has been satisfactorily accomplished 
by first spraying the surfaces to be restricted with a 
Glyptal lacquer followed by the application of an 
industrial tape or by shrinking on a thin rubber tube. 
Here also cork sheeting is used to support the grain 


in the motor and to give it the necessary protection 
against shocks. 

The development of the production techniques de- 
scribed in the preceding paragraphs is the result of 
extensive experimentation which was begun late in 
1941. By the spring of 1042 it had been found pos- 
sil)le to produce satisfactory composite propellants in 
the laboratory. The advantages of the propellants 
were so obvious that the recommendation was made 
to establish a pilot plant which would permit a study 
of production methods and would allow experimenta- 
tion with the product on a sufficient scale to test its 
reliability. In view of the wartime urgency, the de- 
cision was made to build a plant of sufficient capacity 
(500 lb per eight-hour shift) to permit the use of 
production-size equipment and to have an output 
which might itself have some use in Service applica- 
tions. This plant came into operation about the end 
of December 1942. The pilot plant development was 
slower than had been hoped, and somewhat over a 
year was required to demonstrate that a product of 
thoroughly reliable properties could be obtained un- 
der economically feasible conditions. This was partly 
because the process was a completely novel one, in- 
volving operations whose nature was not fully under- 
stood and for Avhich suitable methods of control could 
only be evolved by much investigation, and partly 
because of the occurrence of a series of violent exiflo- 
sions in the milling operation which destroyed the 
mills and occasioned serious delays. Investigation 
showed that with a smaller batch size an ignition in 
the mill led to no serious damage, and the 6-ft mills 
with a several hundred pound batch for which the 
plant was originally designed were replaced by 3-ft 
mills whose operation has been completely satisfac- 
tory. The pilot plant studies during this period were 
almost exclusively concerned with a 2%-in. diameter, 
perforated grain intended for artillery rocket appli- 
cations and upon the 218B composition whose for- 
mula is given in Table 1. By the end of 1943, a com- 
pletely satisfactory product for this purpose was being 
produced, and the process and quality of the product 
had been fully demonstrated. Early in 1944 a change 
was made in the study of the production of 8.5-in. 
and larger diameter charges, the practicability of 
which had meanwhile been indicated by experiments 
at the Explosives Research Laboratory.^® 

At the same time changes in composition resulting 
from investigations at ERL were made. Potassium 
nitrate was substituted for sodium nitrate because of 
the great hygroscopicity of the latter, and an entirely 


tDXi'IDEXrlAQ 


98 


PROPELLANTS 


new type of resinous binder was introduced. The early 
experimentation liad proceeded from the quite ob- 
vious supposition that sufficient fluidity during the 
molding process and sufficient rigidity in the final 
product could only be combined if a thermosetting 
resin is used which is hardened by chemical action 
after the molding takes place. A thermosetting butyl- 
urea-formaldehyde resin, known as Buramine, was 
consequently employed as a binder during the earlier 
development. It was, however, discovered that this 
supposition is quite unjustified, and that ample 
strength and rigidity in the final product can be 
combined with ease of molding without any such 
hardening process, provided a resin of suitable prop- 
erties is chosen.^® 

A binder composed of a highly plasticized ethyl- 
cellulose was found to give as high compression 
strength as the Buramine, and to yield a product of 
considerably less brittleness and greater resistance 
to sudden changes in temperature. It was further 
found that material with a binder of ethylcellulose 
plasticized by Aroclor 1254 could be milled until the 
content of volatile solvents had been reduced essen- 
tially to zero to yield a powder which retains sufficient 
flow for satisfactory molding. With Buramine, by 
contrast, satisfactory flow depended on the presence 
in the molding })owder of a content of butyl alcohol 
lying within a narrow and difficultly controllable 
range; the removal of butyl alcohol after molding, 
without deterioratioji in the quality of the molded 
grain, was extremely difficult. For these reasons all 
recent ])roduction of composite propellants has used 
l)inders of the ethylcellulose- Aroclor type. There are 
indications that still hetter binders may l)e based 
upon rul)bery materials, and that the use of such 
rubbery binders may be needed if grains of 12 in. in 
diameter or greater are to have sufficient resistance 
to fracture from very rapid and large changes in 
temperature.^® 

As a result of the interest of the Air Forces in large 
charges for jet-projoulsion devices and the report of a 
special OSl»I) committee, funds were appropriated 
in March 11)44 for the expansion of the Monsanto 
])ilot plant and its conversion to the production of 
8.5-in. grains. Tempoi-arily the actual molding proc- 
ess was carried on at the Explosives Research Labora- 
tory where a press happened to be available. The high- 
est ])riority was initially given to a development of a 
250-11) thrust, 5()-second hurning-time unit requiring 
a cemented aggregate of three single grains of CF- 
404, each 8.5 in. in diameter and 7.5 in. long, re- 


stricted to burn from one end only. By July 1944, 
it was possible to carry out a successful flight test at 
Tonopah, Nevada, in which two of these units were 
attached to a guided missile launched from an air- 
plane. Performance was satisfactory and the missile 
was given a speed in excess of 400 miles per hour. 

Further development in this direction, however, 
was almost completely stopped for a period of many 
months, because the Air Forces gave the highest pos- 
sible priority to a development of a unit for launch- 
ing the JB-2 bomb, the American copy of the German 
“buzz bomb.’’ For this purpose the charge consists of 
a perforated cylinder, 8.5-in. outside diameter, 2.5- 
in. inside diameter and 36.5 in. long, weighing 120 
lb. This develops at 70 F a thrust of 11,000 lb for 
a ])eriod of 1.85 seconds.^^’^^ Four of these charges, 
each encased in a suitable motor, are attached to a 
launching sled, which, as initially planned, ran on a 
heavy nonportable rail system 400 ft long. By an in- 
genious development of the Air Forces, the bomb, 
sled, and rocket motors are converted to what amounts 
to a free flight rocket. This is launched from a ramp 
only 40 ft long and so light that the whole launching 
system can be permanently attached to a motor- 
drawn trailer or mounted on a relatively small boat. 
This light, highly portable launching system is a 
great advance over the heavy and rigid German 
launchers and various adaptations of those launchers 
which have been studied in this country. 

Some 200 experimental launchings by this method 
had been made at the close of hostilities, with })owder 
produced at the Monsanto pilot plant, with some as- 
sistance from ERL. Rocket performance had been 
demonstrated to have a high degree of reliability and 
the whole launching technique was in a satisfactory 
state of development. 

The JB-2 bomb did not come into combat use, al- 
though a requirement for 500 launching units a 
month existed at the end of hostilities, and the con- 
struction in Texas of a production plant with a ca- 
pacity of 600,000 lb of propellant a month (sufficient 
for 1,200 launchings) was well on toward completion. 
This was to be operated by the Monsanto Chemical 
Company under an Army Ordiiance Department con- 
tract. Interest in the material remains sufficiently 
large so that the Monsanto pilot plant has been con- 
verted to a small production plant with a capacity 
of 75,000 lb per month for peacetime operation by 
the Ordnance Department. 

With the decision to construct the production plant 
in Texas, pilot plant studies and the development of 




SOLVENT-EXTRUDEU COMPOSITE PROPELLANTS 


99 


control tooliniquos for the o})eration of the })ro(luction 
plant became an added responsibility ot* the Monsanto 
pilot plant. At the same time other charges of com- 
posite propellant were in various stages of develop- 
ment. Two types of units had been snccess- 
fnlly but less extensively tested in the Aveapons for 
which they were adapted. Jn one, intended for the 
propulsion of guided missiles, an 8.5-in. diameter 
solid cylinder 23 in. long, weighing 82 lb, treated so 
that it burns from one end only, develops a thrust 
of 250 lb over a period of 48 seconds. A modification 
of this contained a longer charge burning for 65 sec- 
onds, plus a booster charge consisting of an 8.5 x 
15-in. perforated grain to give a high initial accelera- 
tion. In the other type, the decipede, ten individual 

8.5- in. diameter, 8.5-in. long cylinders, burning from 
one end only in a motor provided with multiple 
nozzles, develop a 1,000-lb thrust for 43 seconds. This 
unit is designed to i)ropel, over the surface of the 
water, a demolition device for amphibious operations 
called the Snake. The decipede was developed under 
high pressure and was scheduled for use in the land- 
ings on Japan.^® 

The pressure for immediate development of usable 
jet-propulsion units has led to the neglect of much 
fundamental research and of many interesting but 
longer-range possibilities for improvement of these 
units. Recommendations for future Avork are given 
in many of the Monsanto reports cited in this section 
and s])ecifically in reference 34. 

For comi)lete information about the properties, 
manufacture, testing, and uses of- molded composite 
})ro]K41ants, see references 46 to 64. 

6.3 SOLVENT-EXTRUDED'^^ 

COMPOSITE PROPELLANTS' 

The development of solvent-extruded composite 
})ropellants greAv out of the experience of the Explo- 
sives Research Laboratory Avith molded composite 
})ropellants. These latter materials had most desirable 
ballistic properties, i.e., a Ioav pressure exponent and 
a loAv temperature coefficient, but they Avere not adapt- 
able to the manufacture of long small-Aveb grains 
of the type used in Army-designed rockets such as the 

4.5- in. and the Bazooka; and their brittleness Avas 
a disadvantage, especially in small sizes. Furthermore, 
no plants existed Avhich could be easily adapted to 

^This section is based on a summary supplied by Louis P. 
Hammett and J. F. Kincaid. 


their production. Solveni-exli-uded douhle-base pow- 
der has less satisfactory ballistic pro})ei‘ties, i.e., an 
unpleasantly large i)ressure exponent and tempera- 
ture coefficient, but it is tough and particularly adapt- 
al)le to the manufacture of the long small-Aveb grains 
needed for the rockets in question, l^urther, there 
Avas large plant cai)acity available for its production. 
It seemed Avorth Avhile, therefore, to attempt to com- 
bine the advantages of molded composites and sol- 
vent-extruded poAvders in a single poAvder containing 
a mixture of poAvdered oxidizing and oxidizable par- 
ticles in a matrix of double-base poAvder, the latter 
being present in large enough proportion to permit 
fabrication by the solvent extrusion method. Re- 
search Avas started at the Explosives Research Tjabora- 
tory in August 1943, and by October the desired re- 
sult had been obtained on a small laboratory scale 
in Avhat AA^as called EJA poAvder, Avhich contains po- 
tassium perchlorate as a principal ingredient. Its com- 
position and its excellent ballistic properties are listed 
in Table 2. Its fabrication required only equip- 
ment available in large amounts in existing plants. 
Since the Bruceton laboratory could produce only 
relatively small batches of thin Aveb poAvder, develop- 
ment Avas transferred to the Radford Development 
Department of the Hercules PoAvder Company. Al- 
though the value of the poAvder for the 4.5-in. rocket 
had been Avell demonstrated, methods for the produc- 
tion of material of reliable and reproducible quality 
had not been developed, AAdien, in June 1944, the use 
of this locket Avas dropped by the Air Forces, its 
largest potential user. 

MeaiiAAdiile serious difficulties had appeared Avith 
the Bazooka. The basic theory of this Aveapon assumes 
that the burning of the charge is completed before 
the projectile leaves the muzzle of the projector. The 
double-base charge used in this AA'eapon, hoAA'ever, 
burned beyond the muzzle of the projector AAdien fired 
at a temperature of 70 F or less. This subjected the 
rocketeer to discomfort and even to serious injury 
from the expulsion of poAvder fragments near the 
end of Imrning, and increased the dispersion materi- 
ally. Attempts to improve the situation by modifying 
the granulation led to the danger of bloAvups from 
the high pressures encountered under Avarm Aveather 
conditions. Gun-shy from the painful fragments and 
doubtful of the precision of their Aveapon, Bazooka 
operators Avere suffering severe casualties and Avere 
not getting the desired operational results. A shift 
from the double-base charge to an all EJA charge 
stopped the bloAvups and stopped beyond-the-muzzle 


£ro.\i-'IDKXTIAL;\ 


100 


PROPELLANTS 


Iniriiing uvc*r a range ol‘ teiiiperature iiiueli wider 
than eneonntered in operational nse, but the smoke 
resulting from tlie potassium perchlorate revealed 
the position of the rocketeer and completely excluded 
the use of EJA powder for this or other ground- 
launched weapons. 

After trials with various compositions it was found 
that a powder called BBP (Blastless Bazooka Pow- 
der) or T-4, containing only 7 . 6 ^^ of perchlorate, has 
a temperature coefficient oidy one-half that of the 
standard ballistite. With this powder, hurning can 
be kept within the launcher down to 0 F, and the 
amount of smoke is small enough to be tolerated.'^” 
This powder was immediately adopted for Service 
use, and production started in April 11)45. A new, 
heavier, and more effective Bazooka projectile was 
later designed around this powder and was, indeed, 
possible only because of it. This was upon the point 
of production when hostilities ceased. 

EJA powder and similar materials containing large 
])roportions of potassium perchlorate-carbon black 
filler again became the subject of active study early 
in 1945, since they are ideally suited for use as rate 
control strands in cast double-base charges (Section 
().5), and it then became evident that most of the 
production difficulties encomitered a year earlier 
could be obviated by minor changes in composition. 

Another powder, MJA, also extensively developed, 
contains potassium nitrate instead of the perchlorate 
of EfIA. It is slower burning and has a lower specific 
impulse. It turned out to be ideally suited to the 115 
mm rocket developed at the xVllegany Ballistics Lab- 
oratory, yielding a projectile velocity of 1,200 fps, 
compared with 950 fps from a double-base charge, 
and having a performance essentially independent 
of temperature. Enough powder for extensive tests 
liad been prepared by the Eadford Development De- 
partment when hostilities ceased. Whether the pow- 
der would have reached Service use depended upon 
wliether the 115 mm rocket was finally adopted. This 
in turn depended upon a conflict between the Service 
desire for standardization on a single weapon, the 
II VAR which used large web dry-extruded powder, 
and the availability of large and unused facilities for 
the production of solvent-extruded powder, compared 
with limited and difficultly obtainable equipment for 
dry extrusion. 

These powders are prepared by the methods and 
in the equipment employed for the preparation of 
solvent-extruded gun and rocket propellants. With 
the faster burning compositions such as EJA, exist- 


ing plants are, however, not usable because safety i)re- 
scribes heavier l)arricading and wider dispersal of 
equipment. The ingredients are mixed in a sigma arm 
mixer in the presence of a suflicient amount of volatile 
solvent (ether-alcohol, acetone, or mixtures) to form 
a dough. This is extruded through dies mounted in 
hydraulic presses, and the strands formed are dried 
at temperatures of the order of 130 E or less in a 
curreiit of air for a time which depends upon the 
web thickness and composition of the powder. Ad- 
justment of kind and amount of solvent, time and 
temperature of mixing, temperatm*e and rate of ex- 
trusion, drying time and temperature must all be 
made for each particular composition if powder of 
adequate strength and freedom from flaws is to be 
attained. 

The maximum diameter of solvent-extruded com- 
posite propellants which have been prepared by direct 
methods is approximately 1.5 in. Since the produc- 
tion of larger sizes was desirable, the possibility ol‘ 
dry extruding the solvent-extruded rods or granules 
was investigated. The })roject had passed the pre- 
liminary exploratory stages and serious investigation 
WHS contemplated at the end of the war. A promising 
composition of this type (EDX) is described in 
Table 2. 

The experience in the attempt to transfer a small- 
scale laboratory process for the production of EJA 
powder almost directly to full-scale production equip- 
ment had made it painfully a})pai‘ent that any group 
concerned with the development of new powders 
should have available, under its own direction, an 
experimental plant capal)le of making enough powder 
for extensive testing, and in which the results of 
tests could be immediately transferred to improved 
techniques of production. Xo such expansion was pos- 
sible on the Bruceton grounds, but an agreement was 
made for the construction of an experimental plant 
at the Allegany Ballistics Laboratory, the central lal)- 
oratory of Section IT, NDRt^ Division 3. The tech- 
nical stall and research direction of this ])lant were 
siq)plied by the Explosives Research Ijal)oratory, non- 
technical staff and administration by the Allegany 
Ballistics Tjaboratory. Construction started in June 
1944, and the first batches of powder were made in 
December of the same year. The operations were 
highly successful ; much of the development of the 
BBP and MJA powders was carried out in the Alle- 
gany Ballistics Laboratory, and it was possible to 
turn over to the Eadford Development Department 
essentially complete directions for full-scale produc- 


CAST PERCHLORATE PROPELLANTS 


101 


lion ol' those powdoi's. lii early 1045 the laboratory 
was easily expanded and eon verted to the develop- 
ment of the cast donble-hase charge, including the 
production of the rate control strands. In most respects 
this plant conld serve as a model for an experimental 
developmental establishment for propellants. The 
whole operation was under a single technical control; 
the scale was small enough to permit the production 
of a large number and variety of experimental com- 
positions and large enongh to allow the preparation 
of sufficient powder of the largest granulations for 
reasonably extensive testing in full-scale charges for 
the weapons of interest; and the static and flight 
testing facilities of the Allegany Ballistics Labora- 
tory made possible rapid testing and reporting of 
each new material. 


Table 2. Composition and ballistic properties of solvent-extruded 
composite propellants.* 


Designation 

EJA 

BBP 

MJA 

EDXt 

KClO^t 

56% 

7.8% 

* . . . 


KNO 3 

.... 


43% 

43% 

Carbon black 

9 

1.2 

7 

7 

Nitrocellulose (12.6%N) 

21 



23 

Nitrocellulose (13.1%N) 


54.6 

26 


Nitroglycerin 

13 

35.5 

21.5 

22 

Ethyl centralite 

1 

0.9 

2.5 

5 

I (impulse) 

152 sec 

168 sec 

130 sec 

150 sec 

d (density) 

2.02 g/cc 

1.68 g/cc 

1 .8 g/cc 

1.83 g/cc 

Id 

307 

280 

240 

275 

n (pressure exponent) 

0.45 

approx 0.7 

0.46 

0.54 

R 2000 

1.90 in./sec .... 

0.70 in./sec 1.45 in./sec 

Temp coef 

0.003 

0.010 


0.003 


*7, the specific impulse in seconds, is given for a chamber pressure of 2,000 
psi and unit expansion ratio. The values for other expansion ratios may 
be estimated from OSllD-1027. Because of the greater heat losses with 
the small motor used, the specific impulses given in the table are sub- 
stantially less than those that would be obtained in large motors. The 
small motors which were used give a value of 165 for I and of 270 for I(j, 
for modified Bullseye powder. 

tThe formula for EDX includes 0.6% of added magnesium stearate, 
included to improve extrudability. 

jThe KCIO 4 contains 0.5% magnesium oxide and 0.5% magnesium 
tearate as anticaking agents. 

8 

64 CAST PERCHLORATE PROPELLANTS^ 

llie Calcit proiicl hints, mixtuves of potassium i)cr- 
chlorate and asphalt developed at the California In- 
stitute of Technology, are outstanding for their ease 
of preparation and for the simplicity of the equip- 
ment in which they are prepared. Compared with 
many other propellants they have the additional 
major advantages of a low temperature coefficient of 
the linear burning rate. They have, however, when 
used at very high or very low temperatures, shown 
deficiencies which are probably unavoidable in ma- 

*This section is constructed from material furnished by Louis 
P. Hammett and Harley Hardman.'^'*, 75 


terials of a pitchy or asphaltic nature. Such materials 
become soft enongh to flow at high temperatures and 
become hard and brittle at low temperatures. Since 
it was known that the physical properties of long 
chain, high molecular weight polymers, and espe- 
cially elastomers, change much less with temperature, 
an investigation was begun in the latter part of 1944 
at the Explosives Research Laboratoiy looking toward 
the development of a castable propellant based on 
potassium perchlorate and a suitable high polymer. 

It was clear from the start that the most desirable 
material would be one which was initially a liquid 
of moderate viscosity and which could be converted, 
after casting, to a rubbery polymer by chemical ac- 
tion at not too high a temperature. Materials with 
these properties are not common, particularly when 
the added qualifications are made that the initial 
liquid should not be highly volatile and that its poly- 
merization should not be accompanied by large shrink- 
age. The earliest development made use of a thermo- 
plastic mixture of ethylcellulose and castor oil. A 
2o/7o mixture of ethylcellulose-castor oil and po- 
tassium perchlorate showed some advantages over 
Galcit. This mixture was improved ballistically by 
the addition of 5^ of aluminum flake. It was still, 
however, subject to too narrow useful temperature 
limits. 

The next development was based on the General 
Electric Company’s Permafil resins. These resins are 
sufficiently fluid originally to permit casting a suit- 
able mixture with potassium perchlorate at room tem- 
perature. In the presence of a peroxide catalyst the 
mixture sets up overnight at 60 C to a gel of about 
the consistency of art gum. After polymerization the 
mixture does not flow at 140 F and is still rubberlike 
at — 40 F. The recommended composition is 

74.5^ potassium perchlorate, 

0.5^ carbon black, 

^ 24.G% I'crmafil 285], 

0.33% /-butyl perbenzoate. 

The process involves grinding the perchlorate to a 
controlled particle size; mixing the ingredients in a 
kettle or dough mixer, preferably under vacuum ; 
casting in suitable metal molds; heating at 60 F for 
two days; removing the casting from the mold; and 
applying the restricting material to the casting. 

The product obtained in this fashion has a specific 
impulse of 170 seconds at 1,000 psi and optimum ex- 
pansion, a density of 1.81 g per cc, an exponent of 
0.70 in the burning law, a burning rate of 0.72 in. 


1 (I\I-I1)KVtTa1^ 


102 


PROPELLANTS 


])er 80 ('Oii(l at 1,000 psi and 10 F, and a rnstrietiun 
ratio ot' 182 under tlie same eunditions. ddie teinpera- 
tnre eoeffieient of pressure, thrust, and burning- time 
at constant restriction ratio is 0.6 per degree 
centigrade. 

This development was so promising that a pilot 
})lant for further study of the preparation and prop- 
erties of east percldorate ])ropellant was designed 
and liad been partly constructed by the time hostili- 
ties ceased. Further work remains to be done, par- 
ticularly to secure neutral buriiiug and to permit 
restriction of huruiug surfaces for low temperature 
tiriiigs, before the cast perchlorate propellant can he 
considered a completed development. There seems 
to be no reason to doubt, however, that this addi- 
tional work can be carried through successfully. 

65 CAST DOUBLE-BASE POWDER" 

During the course of World War II it became ap- 
parent tliat there were needs for giant grains of rocket 
propellants for a number of important applications. 
These applications included towing of “Snakes’’ for 
mine clearance, assisted take-oH of aircraft, and the 
launching and propulsion of guided missiles. By the 
fall of 1944, two types of rocket propellants, molded 
composite propellant and Galcit (see Sections 6.2 
and 6.4), had been developed to fdl these needs. While 
both these materials had many excellent characteris- 
tics, they had one defect in common : both produced 
large volumes of white smoke on firing. This made 
them unsuitable for many applications. Double-base 
l)owder, by contrast, is smokeless, but, unfortunately, 
no fabrication method existed which was suitable for 
the preparation of sufficiently large grains of double- 
base powder for these applications. 

In the fall of 1944 work was begun at the Explo- 
sives Research Laboratory looking toward the devel- 
opment of a method of fabricating very large grains 
of double-base powder by exploiting the tendency of 
nitrocellulose strands or granules to swell and coales(^e 
when immersed in a suitable solvent. It was hoped 
that a solvent which was sufficiently nonvolatile, suffi- 
ciently active, and which had adequate explosive po- 
tential could be devised by mixing a liquid explosive 
such as nitroglycerin with some reasonable pro 2 )ortion 
of a nonvolatile nonexplosive material. It seemed 
^mssible that when the slurry of finely granulated 
nitrocellulose-base propellant was mixed with the 

"This section is constructed from information supplied by 
John F. Kincaid. 


solvent the granules of casting ])o\vdcr would coalesce, 
due to the diffusion of liquid into the nitrocellulose 
ajid the resulting increase in the volume of the solid 
phase. In preliminary experiments to test this hypoth- 
esis, a mixture of 80 parts of nitroglycerin and 20 
})arts of diethyl phthalate was chosen as solvent for 
tlie initial test. A hall j^owder having a mean ball 
diameter of 0.020 in. was available. The initial cast- 
ings were prepared by forming a slurry of the two 
ingredients, evacuating to remove air, and curing for 
two days at 60 C. Partial burning of the castings at 
8,000 psi indicated that they were of excellent quality. 
The partially burned surfaces were perfectly smooth, 
aside from a faint surface |)attern reminiscent of the 
original heterogeneous structure of the slurry. Be- 
cause this preliminary experiment was so successful, 
serious attention was immediately given to the devel- 
oi)ment ])rol)lems involved. 

In January of 1945, enough cx 2 )erimental data had 
been collected to make it reasonably clear that the 
process worked essentially as outlined above, and the 
industrial develoinnent of the process appeared to l)e 
a feasible undertaking. At that time a new j3i-inci})le 
for controlling the burning rate, tenq)eratnre coetli- 
cient, and pressure exponent of double-base pro])el- 
lants was suggested by the California Institute of 
Technology. The proposal was that a number of 
strands of some material having good ballistic char- 
acteristics be imbedded in an end-burning charge of 
doul)le-hase powder in the form of long strands run- 
ning parallel to the axis of the grain. It is necessary 
that these strands l)e faster burning under all 023erat- 
ing conditions of tenqjerature and pressure than the 
matrix which surrounds them and that they be tightly 
bonded to the matrix so that burning cannot j^roceed 
down the junction of the two materials. This method 
of controlling the ballistic characteristics of cast 
double-base propellants Avas particularly attractive 
since the material of choice for the rate control 
strands, solvent-extruded composite jArojAellant was 
at hand as the result of an earlier development (see 
Section 6.3). Solvent-extruded composite propellants 
have excellent ballistics. They produce smoke on 
burning and they are difficult to prepare in large 
Avebs, but these tAvo disadvantages AA^re not of im- 
])ortance in their use as rate control strands, since 
the proportion required (1 to 2^/c) Avas too small for 
the smoke to be significant, and the rate control 
strands need not have large diameters. 

The combination of the casting process for fabricat- 
ing double-base poAvder Avith the rate control plan in- 




CAST DOUBLE-BASE POWDER 


103 


trodiurd tlio possibility of })i' 0 })afiiig [)ropcllants com- 
bining all the advantageous properties of both straight 
double-base and solvent-extruded composite i)ropel- 
lants. These included the good mechanical properties, 
smokelessness, and high impulse characteristic of 
doul)le-base propellants, with the tlexibility of burn- 
ing rates and low temperature coefficients charac- 
teiistie of the composite materials. The nnique ad- 
vantage to be gained by such a grain (later christened 
Type 1 castings) may be illustrated by discussing an 
old problem frequently encountered. In double-base 
])owders and to some extent in composite propellants, 
there exists a correlation between the flame tempera- 
ture and the burning rate of the materials. The faster 
burning materials, having high dame temperatures, 
are required for many applications. At the same time 
low llanie temperatures are frequently desirable in 
order to eliminate Hash and reduce nozzle erosion 
and motor heat-up. It can be seen that the rate con- 
trol plan offered, for the first time, the possibility 
of independently controlled flame temperature and 
burning rate, since the burning rate can be varied 
by variations in the rate control strands which con- 
stitute too small a proportion of the entire charge to 
be therniochemically significant. 

Until the proposal of the rate control principle, 
the research objectives of the group Avorking on the 
cast double-base process had not been clearly defined, 
since attention Avas directed toAA^ard a general study 
of the significant features of the process. After this 
plan became available, hoAvever, it Avas clear that an 
end-bnrniug charge could be constructed having a 
diameter of 8 to 9 in. and operating at a pressure of 
1,500 psi or less, Avhich Avould deliver a thrust of 
1,000 11). Such a charge Avould be smokeless, could be 
loaded into the currently available Aero Jet motors, 
and, since it Avas end burning, Avould completely fdl 
the available motor space aside from the volume re- 
(piired for restriction and a reasonable clearance, 
ddiis ('barge Avas considered to be an ideal answer to 
tbe Navy’s need for an 8-second, 1,000-lb thrust, 
smokeless unit for the jet assisted take-off of aircraft 
from carriers, and the development of this charge 
Avas made the top objective of the group. 

The status of this development program Avhen 
NDliC Avork Avas terminated in November 1945 is 
outlined beloAV. 

Composition 

The effect of variations in composition on the 
mechanism of consolidation has been extensively 


studied at the Nx})losives Ivesearch Laboratory and 
at Cornell University. The significant variables ap- 
pear to be Avell understood. For example, it has been 
demonstrated that matrices of good (piality can be 
obtained consistently. Tdie effects of varying the 
composition of the casting poAvder and/or the com- 
position of the solvent have been thoroughly studied, 
and it has been possible to find quick solutions for 
the development difficulties which hav^e arisen from 
time to time. The composition of the casting poAvder, 
casting sohent, and rate control strands AAdiicli are 
currently standard for this application are given 
bcloAV. 


Casting Powder Per Cent 

Nitrocellulose (13.15% N) 74 

Nitroglycerin 20 

Diethyl phthalate 5 

Centralite 1 

Carbon black (added) 0.5 

Casting Solvent Per Cent 

Nitroglycerin 65 

Dimethyl phthalate 34 

Centralite 1 

Rate Control Strands Per Cent 

KCIO4 56 

Carbon black 9 

Nitrocellulose (12.6% N) 25 

Casting solvent 9 

Centralite 1 


Fabrication Methods 

Tavo fabrication methods are currently favored. 
One, thoroughly studied by the Division 8 group at 
the Allegany Ballistics Laboratory, is knoAvn as the 
increment method. In this method the grain is fabri- 
cated by successive additions of casting poAvder and 
solvent in increments to the container. A previous 
evacuation of the ingredients alloAVs the formation of 
a product free of holes. The ingredients are mixed by 
carrying out the addition Avith the container mounted 
on a shaking machine of industrial design. The rate 
control strands are held in place by spiders at the top 
and at the bottom of the container and are mounted 
in place before the addition of the other components. 
Another method proposed and initially developed by 
a group Avorking at the Kenvil Plant of the Hercules 
Powder Company is knoAvn as the bottom- filling meth- 
od. In this method the evacuated casting powder and 
the rate control strands are placed in the container 
before any solvent is added. The evacuated solvent 
is then flowed into the container through a hole in the 
bottom under a graAuty head. The bottom-filling 


104 


PROPELLANTS 


inetliotl lias received soiiiewliat less attention than the 
increment loading method, but experience Avitli it has 
been highly favorable, and it is anticipated that this 
method Avill he an excellent industrial fabrication 
technique. 

Restriction 

After preliminary experiments it Ayas decided that 
end-bnrning grains of the type desired could best be 
prepared by casting the components into a plastic con- 
tainer AA'liich AATinld then serve as the restrictive coat- 
ing Avithont additional modilications. This method has 
proA’en to lie highly successful and convenient. After 
an investigation of a large number of plastics, includ- 
ing Saran, a number of vinyl polymers, Bakclite, 
Beetle, cellulose acetate, cellulose acetate butyrate, 
Lucite, ethylcellulose, and polystyrene, the field Avas 
narroAA^ed to cellulose acetate, ethylcellulose, and Lu- 
cite. Other materials either proved to be too inert to 
bond Avith the castings, e.g., Saran, or softened too 
readily under the influence of the nitroglycerin, e.g., 
cellulose acetate butyrate. Currently, cellulose acetate 
is regarded as the best material for restrictiA^e con- 
tainers. The containers actually used have been largely 
fabricated by a convolute Avrapping method from 10- 
mil cellulose acetate sheets, but an injection molding 
method appears feasible and should be investigated. 

^ . Service Evaluation 

A})})roximatcly dOO grains 8 V 2 in. iu diameter and 
AA'cighing 40 to 75 lb have been prepared. Evaluation 
of the experience gained Avith these gi’ains and Avith 
some 1,400 subcaliber units 4 in. in diameter leads to 
the folloAving conclusions. 

Grains AAdiich haA’e satisfactory ballistic characteris- 
tics at room temperature and elevated temperatures 
can be consistently prepared. There remain some diffi- 
culties Avith loA\-temperature firing behavior and Avitli 
cycling, but it appears probable that additional devel- 
opment Avill solve these difficulties. The high-tempera- 
ture aging characteristics of the centralite-stabilized 
composition given above are not so good as Avonld be 
desirable, and considerable effort has gone into the 
study of this characteristic. Failure on storage at high 
temperatures is caused by the formation of gas Avithin 
the grain. Gas formation is a normal phenomenon for 
double-base poAvders, ])ut difficulty Avith it had not ap- 
peared until rather large grains Avere fabricated. This 
is due to the ease Avith Avhich the gaseous decomposi- 
tion products can diffuse through thin Aveb materials. 
It has been observed that the sid)stitution of carbazole 


for central ite as a stabilizer causes an enormous in- 
crease in the high-tempefature storage life. While 
carbazole-stabilized materials are unsatisfactory, due 
to difficulty Avith consolidation, a ncAv stabilizer, 2- 
nitrodiphenyl amine, has been discovered Avhich, it is 
hoped, Avill have the advantageous characteristics of 
both centralite and carbazole. The possibility that the 
normal exothermal decomposition reaction of such 
large grains AA'ould cause self-heating and eventual 
spontaneous explosion has been carefully studied, and 
it has been found that no difficulty from this can be 
expected Avith solid grains 8 V 2 in. iu diameter. It is 
probable that very much larger gi-ains can also be 
safely prepared. 

ft seems probable that cast donl)le-base propellants 
are a nearly ideal material for the fabrication of very 
large grains for thrust applications. Type I grains, 
those having axially dispersal rate control strands, 
appear to be particularly suitable for thrust units 
having l)urning times of 8 seconds or more, and thrusts 
of 500 to 2,000 11). Double-base castings Avithout rate 
control poAvder (Type 0), or castings containing rate 
control poAvder in the form of uniformly dispersed 
granules rather than long strands (Type II), can be 
used for the fabrication of single or multiperforated 
grains having short burning times and high thrusts. 
Since such short-hurning, high-thrust units appear to 
be badly needed for the launching of guided missiles, 
additional development Avork on Ty])c 0 and Type IF 
castings is very much in order. Development of these 
materials has thus far been of a preliminary character 
ouly, since so much emphasis Avas placed on the devcl- 
o])ment of the Type I castings. 

A number of specific recommendations for future 
Avmrk are possible in the light of this experience. The 
more important of these folloAV. 

1 . Type 0 and Type 11 castings should be carefully 
investigated. 

2. The consolidation and ballistic characteristics of 
castings prepared from casting poAvder containing Ioav 
nitrogen (12.6 or 12.2% N) rather than high nitrogen 
(13.15% N) stock should be investigated Avith the ex- 
pectation that the consolidation characteristics of such 
casting poAvder Avill be much better than those of the 
standard poAvder iioav in nse. This Avould alloAv the 
preparation of many compositions AAdiich Avould not 
consolidate Avell if nitrocellulose of high nitrogen con- 
tent AA^ere used in the casting poAvder. 

3. 2-Nitrodiphenyl amine, and, possibly, other sta- 
bilizers, require careful and large-scale evaluation, in 
AieAv of the observation at the Explosives Research 


€SfTT).Eim4Q 


NOZZLE DESIGN AND MATERIALS 


105 


I^aboratory that the rale ot gas pi-oduetion 1‘roin 
douhle-base powder varies enormously with the 
stabilizer. 

4. Additional study of the fabrieation of eontain- 
ers and of their storage life at normal ambient tem- 
peratures needs to be earried out. An injection mold- 
ing method of fabrieation is particularly recommended. 

6 6 NOZZLE DESIGN AND MATERIALS' 

The work of the Explosives Research Laboratory 
on the develo})ment of new jet ])ropellants, described 
in Sections to (>.5, required the construction of 
motors for static tiring tests. As interest in jet pro- 
pellants turned to large long-burnijig charges, the 
prohlem of erosion of the motor nozzles became acute. 
Large numbers of charges had to be tested, and the 
fabrication of nozzles was both expensive and a seri- 
ous burden on machine-sho}) facilities. Further, no 
adequate conclusions could be drawn about the be- 
havior of a single propellent charge unless the throat 
area of the nozzle remained essentially constant dur- 
ing the burning. For these reasons the requirements 
for test motors are more severe than for Service motors, 
and it was necessary to study, as a problem in itself, 
the design and construction of nozzles. 

The conclusions from this stndy®'’*^ are consistent 
with the idea that a nozzle erodes or does not erode 
depending on whether the tem])erature of the surface 
layer exceeds or does not exceed the melting point of 
the nozzle material. There is no evidence to suggest 
that specific chemical attack is involved oi’ that the 
high-temperatnre strejigth of the material is of im- 
])oitance. The same conclusiojis have appeared from 
work on gun erosion. More specifically the results arc : 

1. The hame temperature of the propellant is a 
major factor. Because the necessary thermodynamic 
data for the accurate calculation of the temperature 
of propellants containing large quantities of alkali 
salts are lacking, this conclusion is qualitative rather 
than quantitative; but the difference in erosion be- 
tween composite propellants containing 10 to 15% of 
alkali nitrate and those containing around 50% of 
alkali nitrate are very large and unmistakable. The 
more erosive compositions with higher nitrate content 
undoubtedly have higher flame temperatures. 

2. Erosion increases markedly with increasing 
chamber pressure. The effect is large and of great 
practical importance. 

‘This section is constructed from a summary prepared by 
L. Axelrod. 


5. Erosion is greatest at the throat and in the near- 
by regions upstream in the gas flow. If this region can 
be i)rotected against erosion, no other need give con- 
cern except when grid supports or other obstacles di- 
rectly interfere with the gas floAV. 

4. The melting point of the nozzle material is of 
prime importance. Molybdenum, which may take the 
form of a relatively small insert in the critical throat 
area, has been most serviceable. Pure chrominm and 
tungsten carbide have also performed well in limited 
tests. Heat capacity and conductivity are also import- 
ant, since higli values lower the surface temperature; 
copper is consequently more resistant than steel. For 
the same reason the mass of the nozzle is a factor of 
importance, and a large, heavy nozzle is more resistant 
than a small, light one. xVlloys, AAdiich have loAver con- 
ductivity and usually lower melting points, are less 
resistant than pure metals. 

5. Given the same propellant and the same burning 
time, erosion is more severe Avith small charges than 
Avith large charges because the former require the use 
of small nozzles. This conclusion is definite and based 
on comparative tests Avith tAAm different propellants. 
The effect probably arises from the fact that nozzle 
mass and heat capacity vary as the cnhe of the linear 
dimension, heat transfer as the square. 

6. The geometry of nozzle and of nozzle entrance 
area are of overAA'lielming importance. Designs l)ased 
on qualitative considerations of reducing turbulence 
in the gas floAV have led to a great decrease in erosion. 
Hiifortunately no quantitatiA^e theory is available but 
Figure 2 illustrates the points AAdiich have been found 
empirically to be significant. 

a. The gas former region should be the frustum of a 
cone extending to the full diameter of the motor. 
A 45° angle is satisfactory. ReAerse curvatures 
(S-shaped confignrations) have not performed 
Avell, probably due to the fact that a small radius 
of curvature becomes necessary in the entrance 
if the curvatures in the gas former, entrance, and 
throat are to blend AA^ell into one another. 

b. The gas former should be tangent to the curva- 
ture of the entrance of the nozzle. The radius of 
curvature p of the entrance should be as large 
as possible. 

c. This curvature should carry through the throat 
and blend smoothly into the expansion cone. 
There should be no straight portion at the throat. 
Nozzles designed according to this scheme have 
the same radius p, about a center F, from the 45° 


( CoNL-lDKX'rixVir^ 


106 


PROPELLANTS 


cone through the throat and to the o0° expan- 
sion cone. 

d. All irregularities should be avoided and finish 
should be smooth, though a high i^olish has not 
appeared to be necessary. 

e. The wall thickness of the nozzle and hence its 
total mass can be adjusted by cut and try pro- 
cedures to the propellant and burning time con- 
cerned. 

f. The expansion angle has little effect on the effi- 
ciency of the nozzle, provided the angle is be- 
tween 20° and 40°. 


F 



Figure 2. Geometry of nozzle and nozzle entrance area. 


AVith nozzles designed in this way of steel or, for 
more severe conditions, of copper, satisfactory per- 
formance for single shots has been attained with all 
of the charges of interest to this laboratory. Most 
nozzles will also Avithstand numerous repeated shots. 

Some special observations have been made on par- 
ticular materials. Steel nozzles of proper design to 
withstand repeated firings usually fail by the appear- 
ance of checks on the throat. These checks enlarge to 
cracks in which extensive erosion then takes ])lace. 
Under the same condition copper fails, if it fails at all, 
by actual melting. Comparative tests under highly 
erosive conditions showed that the resistance of iron 
alloys decreased in the order SS501, SAE 2515, 
SS440, SS4321, and Armco iron. Tests on steel and 
copper nozzles coated with tungsten, molybdenum, or 
chromium showed little if any advantage gained by 
the coating. In one nozzle a thin sheet of tantalum was 
rolled inside a steel nozzle to conform to its contours. 
This survived several shots, after Avhicli blisters 
formed and eroded. The chief difficulty with all types 


of coatings is to obtain sulficient adherence to the base 
metal. Most coatings tear off during the tests. 

Graphites investigated in the form of large inserts 
supported in steel were the C-18, AGX, A12, and 
AMF grades of the National Carbon Company. They 
had densities varying from 1.52 to 1.61). The lower 
density grades tend to erode, the higher density ones 
to crack. Usable nozzles for some applications have 
been made, but Avell-designed metal nozzles are prob- 
ably more reliable. 

Many ceramic materials have been tried as inserts. 
All eroded and many cracked from thermal shock. In 
view of their light Aveight and economy in mass pro- 
duction they may AA'ell deserve further study, particu- 
larly in the direction of using very high-melting ox- 
ides bonded Avith a minimum amount of fluxing agent. 

67 ALBANITE POWDERS^ 

At the outset of World War II, an urgently needed 
improvement in gun performance Avas the elimination 
of secondary flash from 6-in. to 8-in. caliber cannon. 
The current propellant of least flashing tendency, 
namely FNH Avith incorporated potassium sulfate, 
did a passable job in guns up to 5 in., but it Avas ob- 
jectionably smoky and it flashed in all the larger 
Aveapons. Early in 1942, the problem rose dramatically 
in importance Avith the advent of nighttime naval 
engagements, Avhen the blaze of flight from the ship’s 
oAAUi guns so blinded its personnel as to interfere Avith 
fire control. 

In Project NO- 13 5, the Navy asked Division 8 to 
develop flashless propellants for pertinent existing 
guns. Work Avas begun at the Explosives Research 
Laboratory, and, beginning in May 1943, promising 
formulas Avere carried into the semi-Avorks phase 
under Contract OEMsr-763 Avith the du Pont Com- 
pany ; this study led to the first proof firing of Albanite 
in March 1944.*^ 

Preparation of pilot scale quantities of Albanite ex- 
tended from July 1944 to November 30, 1945, under 
Contract ()EMsr-1355, also Avith the du Pont Com- 

jThis section is constructed from a report written by H. 
H. Holmes. 

•'For details of the work done at the Explosives Research 
Laboratory, see reference 83; for details of the work done at 
the Burnside Laboratory of the Explosives Division of E. I. 
du Pont de Nemours & Company, see reference 84. Small- 
scale studies of the preparation and properties of solventless 
powders containing DINA and other materials in place of 
nitroglycerin are reported from the California Institute of 
Technology's and are discussed in Section 6.10. 




ALBANITE POWDERS 


107 


paiiy. The success of the powder in medium-sized guns 
prompted its trial in cannon as large as 16 in. and in 
smaller weapons down to 40 mm, the latter with the 
hope of obtaining ammunition which is at the same 
time smokeless and flashless. 

The only promising solution of the problem lay in a 
propellant having a flame temperature lower than that 
of Pyro or FXH. The low heat evolution and high gas 
volume of nitroguanidine strongly recommended its 
use; indeed, nitrognanidine had been tested several 
times during the last fifty years and had been rejected 
principally for lack of a ready supply in this country. 
By 1943 Canada was making nitroguanidine in com- 
mercial quantities, and the British were using in 
some of their guns the following composition, called 
Cordite N. 


Nitrocellulose (13.1% N) 19.0 parts 

Nitroglycerin 18.5 “ 

Nitroguanidine 54.7 “ 

Ethyl centralite 7.5 “ 

Cryolite (KsAlFe) 0.3 “ 

Chalk 0.15 « 


Cordite N is about equal in force to Pyro and NH, 
and its estimated flame temperature is 2430 Iv, as com- 
pared with 2580 K for the two American powders. Two 
disadvantages discouraged its adoption by the United 
States: (1) the health and explosion hazards of nitro- 
glycerin volatilization and (2) the low mechanical 
strength of the composition in multi perforated grain 
form, especially at low temperatures. Samples of Cord- 
ite N, with 1.5% K2SO4 added, were made at the 
Nobel Works of Defense Industries, Limited, for the 
Navy 6-in./47 gun; in tests at the Naval Proving 
Ground, the powder gave essential flash suppression 
under severe conditions and was superior to the best 
single-base combination, FNH -[-4% K2SO4. Cordite 
N later was proved flashless in major caliber cannon, 
and the Navy procured several million pounds from 
Canada as a temporary expedient; the fleet, however, 
never used it in regular operations, so that the experi- 
ments served principally to clear the way for a nitro- 
guanidine formula containing a less volatile substitute 
for nitroglycerin and having good physical properties. 

The physical incompatibility of nitroguanidine with 
nitrocellulose demands a high proportion of plasticizer 
in order to secure workability and strength in the fin- 
ished colloid. It follows that most of the plasticizer 
content must have explosive potential. A paper survey 
of the explosives field eliminated most compounds on 
one or more of the following counts : volatility, lack of 
plasticizing action, chemical instability, sensitiveness 


to detonation, hygroscopicity, unavailability. The re- 
maining candidates then were prepared and incorpo- 
rated into a propellant formula similar to Cordite N. 
The candidates were : 


Common Name 

Emmett 

GGTN 

GLTN 

DINA 

Fivonite 

Sixonite 


Chemical Name 

Ethyltrimethylolmethane trinitrate 
Glycerol monoglycolate trinitrate 
Glycerol monolactate trinitrate 
Bis-nitroxyethyl nitramine 
Tetramethylolcyclopentanone tetranitrate 
Tetramethylolcyclohexanone tetranitrate 


Emmett was rejected for lack of solubility in nitro- 
cellulose and because it was about half as volatile as 
nitroglycerin. GGTN was dangerously unstable in the 
free state and in propellent mixtures. GLTN was un- 
attractive because of difficulty in preparing the mono- 
lactate free from unesterified glycerol. Sixonite proved 
generally similar to Fivonite but had a lower potential 
with no compensating advantages. Of the two remain- 
ing explosives, DINA exhibited fair plasticizing action 
and was only one-tenth as volatile as nitroglycerin, and 
Fivonite was still less volatile, but compared with 
DINA it was relatively low in potential and was a 
poor plasticizer. In view of the current emphasis on 
low volatility and the urge for speed in development, 
DINA emerged as the most expedient material. 

Propellant manufacturing techniques and ingre- 
dients then were studied on a 10-lb batch scale with a 
4-in. diameter extrusion press, pointing for a medium- 
caliber powder which could be made in the plentiful 
American solvent-type equipment. Pyro nitrocellulose 
(12.6% N,8- to 20-second viscosity at 10% in acetone- 
alcohol) produced the toughest and most workable 
colloid out of a list including 13.15% N blends of 13.4 
and 12.6, with high, normal, and low viscosity; 13.0% 
N direct-nitrated; 12.0% N direct-nitrated. Various 
combinations of acetone, ethyl ether, and ethyl alcohol 
were tried as volatile solvents, and acetone-alcohol 
from 1/1 to 2/1 was chosen on the basis of workability 
and ingredient dispersion. Mechanical grain strength 
was markedly improved by replacing part of the cen- 
tralite with a more active nonexplosive plasticizer, e.g., 
dibutyl adipate, dibutyl phthalate, triacetin, or DNT 
oil. (Other effective, but less attractive, adjuvants 
were Nylon, Neoprene, or ethylcellulose. Surface active 
agents such as soya lecithin or stearylamine were only 
slightl}^ effective.) The manufacturing process com- 
prised mixing at 45 C with 13 parts acetone-alcohol 
per 100 parts powder formula, blocking, extruding in 
multiperf orated form, cutting to the same grain length 


$'0\F[DKyTT.\i:i 


108 


PROPELLANTS 


as corresponding NH powders and drying in air at 
50 L for 5 days more or less, depending on web size. 
Out of this research came the Al])anite formula. 


Nitrocellulose (12.6% N) 20.0 parts 

DINA 19.5 “ 

Nitrogiianidine 55.0 “ 

Dibutyl phthalate 4.0 “ 

Ethyl centralite 1.5 “ 


100.0 “ 

K 2 SO 4 to suit pertinent weapon (1.5 

parts K 2 SO 4 for 6-in./47 gun) 0 to 5 parts 

Volatile solvent (approx) 0.2 “ 

Moisture, less than 0.1 “ 

Adiabatic flame temp (1.5% K2SO4) 2390 K 

Potential (C^To, cal/g) 870 

Force relative to Pyro powder 98% 

Burning rate relative to Pyro (ai)prox) 75% 


A sample of Albanite, meeting standard ballistic 
specifications, was fired in the 6-in./47 in comparison 
with (1) an analogous sample made with Fivonite, 
(2) Cordite N + 1.5% K^SO,, (3) Pyro + 4% 
1X2^04 and (4) regular Pyro. Albanite and its Fivon- 
ite analog were essentially flashless under the most 
severe conditions. They were marginally superior to 
Cordite N, and all the nitrognanidine powders were 
far superior to the Pyro samples which gave blinding 
flashes of greater or less intensity. 

Albanite has these further advantages over Pyro 
and Nil : low hygroscopicity (0.3% moisture at equi- 
librium in 90% relative humidity at 30 C), and low 
residual solvent content, both making for ballistic 
stability; and a reasonable expectation of lower gun 
erosion rate. NDliC, Division 1, tests at the Franklin 
Institute place ('ordite N and Albanite among the least 
erosive of current propellants.*® Navy gun firings have 
demonstrated double gun life for Cordite N versus 
Pyro, and performance at least as good is expected for 
Albanite. Its chemical stability appears assured in that 
samples have withstood storage at 65.5 C for more than 
two years without a failure.*®’*^’^® Its grain strength, 
according to side impact test, is only about 70% of 
Pyro or Nil at —20 C, but is 170% of Cordite N at 
the same temperature. 

Phase equilibrium studies at Cornell University*^ 
showed that DINA is soluble in Pyro nitrocellulose to 
the extent of only a 23/77 ratio at 26 C. The rate of 
crystallization of DINA from a 50/50 supersaturated 
colloid, however, is very slow. Microscopic examina- 
tion of finished Albanite grains revealed some 5% of 
the DINA crystallized on or near the surface, but the 
})roportion of* crystals did not increase appreciably 
during several months’ storage, and no significant 


internal crystallization was detected. A storage pro- 
gram coupled with closed chamber burning rate tests 
revealed no change in ballistic properties during 9 
months’ storage at the following temperatures ; — 40 
C ; 40 C ; cycling between — 40 C and + 40 C ; at- 

mospheric temperature. Special tests proved that sub- 
stantially no DINA dust can be removed from the 
grain by tumbling. The crystallization of DINA, there- 
fore, is not regarded as an important quality factor. 

An analytical procedure for estimation of the pro- 
portions of the ingredients in Albanite was developed.** 
Toluene is used to extract DINA, centralite, and 
dibutyl phthalate. DINA is determined hy volumetric 
reduction with ferrous ion, centralite by volumetric 
bromination, and dibntyl phthalate by difference. Ni- 
trocellulose is weighed as such after water extraction, 
and potassium sulfate is determined by a conventional 
method in the water solution. Nitrognanidine is esti- 
mated by difference. 

Although the solvent-wet colloid and finished Al- 
banite are insensitive to detonation by 100 grams of 
60% straight dynamite, dry nitrognanidine and its 
mixtures with nitrocellulose are cap sensitive. Further, 
the wet colloid contains so little solvent that its burn- 
ing rate in mixers and presses is several times higher 
than single-base colloid, approaching that of 40% 
double-base solvent-type powder. It was unsafe, there- 
fore, to make large trial lots in existing single-base 
factories where the operators are directly exposed to 
the equipment. Since suitable American capacity was 
not available in the summer of 1944, it was arranged 
to make three lots*^ at the Winnipeg Works of De- 
fense Industries Laboratory, using DINA and Pyro 
(wood pulp), nitrocellulose made at de Salaberry 
Works : 

46,400 lb for 6-in./47 (1.5% K2SO,) 
lot VC-66-EX 

3,000 lb for 8-in./55 (5% 
lot YC-97-EX 

15,000 lb for 16-in./45 (5% KgSO^) 
lot YC-96-EX. 

Manufacture was carried out in the machines regularly 
used at Winnipeg for Cordite N. Crystalline DINA 
was dissolved in acetone, and the solution added to 
the other ingredients in a kneader holding about 430 
lb of powder formula. The mixed colloid was hand- 
tamped directly into 8-in. vertical extrusion presses. 
There was no macerating, blocking, or macaroni 
pressing equi])ment. Considerable experimentation 
and extension of mixing time were required to arrive 


ALBANITE POWDERS 


109 


at a treatment which would completely disperse the 
nitrocellulose without the use of excessive quantities 
of volatile solvent. Especially in the 8-in. and 16-in. 
granulations, porosity in the form of solvent-air bub- 
bles resulted in variable burning rates from batch to 
batch, and it was indicated that blocking and macaroni 
pressing might be required in eventual full-scale manu- 
facture. Although careful bomb firings of batches and 
subsequent blending resulted in acceptable lot quick- 
ness, the finished grains were objectionably porous. 

In proof firings in the respective guns, all three lots 
were liashless. Smoke density was greater than with 
standard flashing powders, as expected, but was judged 
acceptable by modern battle standards. Lots VC-Ol- 
EX and VC-9 6-EX performed within the velocity and 
pressure specifications, and gave satisfactory velocity 
uniformity. Although lot YC-66-EX (6-in./47) dis- 
played poor uniformity when initially fired, later 
trials, in which the previous round effect was elimi- 
nated, resulted in generally satisfactory uniformity 
and acceptable velocity and pressure levels. 

At the conclusion of these tests in the spring of 
1945, a practical solution of the problem appeared 
within reach, processing difficulties notwithstanding. 
In the interest of speeding the development, the com- 
position for the time being was regarded as fixed, and 
the final steps — process improvement, preparing addi- 
tional proof lots for large guns, and arranging full- 
scale manufacturing facilities — were started almost 
simultaneously. 

An OSHD pilot plant had been under construction 
at Burnside Laboratory since September 1944. Tt was 
designed for the safe investigation of hazardous pro- 
pellent mixtures in full-sized machinery, and to this 
end the mixers and presses were surrounded with 10- 
in. reinforced concrete walls, covered with a light roof 
and remotely controlled. The principal equipment 
items were a solvent mixing tank, two 50-gallon 
Werner-Pfleiderer mixers, one macerator, one 11%-in. 
blocking press, one 12-in. vertical extrusion press (also 
used for macaroni pressing), two cutting machines, 
and an air-drying house. Operation began on Albanite 
in February 1945. Between that date and November 
1945, in the course of process studies some 200,000 lb 
of Albanite were made at Navy request.®'’ 

In view of the fact that DINA, either crystalline 
or molten, is almost as sensitive as nitroglycerin, it 
was desensitized at the Eastern Laboratory nitrating 
plant by mixing 90 parts molten DINA with 10 parts 
dibutyl phthalate.®^ The mixture, termed DDF, was 
received at the Albanite plant as a relatively insensi- 


tive frozen mass in metal pails of 50 lb net weight. 
The DDF was then melted by surrounding the pails 
with water at 70 C, and was poured into a solvent mix- 
ing tank, which already contained the acetone and 
additional dibutyl phthalate called for by the powder 
formula. The resulting ‘^solvent mix” was ready for 
addition to alcohol-wet nitrocellulose, nitroguanidine, 
and potassium sulfate in the powder mixer. 

A mixing treatment of about 2 hours at 45 C jacket 
temperature, with 300 lb net powtler per charge, was 
required to disperse the nitrocellulose. The colloid was 
then cooled and stiffened by evaporating part of the 
volatile solvent in the macerator, after which it was 
blocked at 1,000 psi. Efforts to extrude the powder at 
this stage resulted in a highly porous grain. Greatly 
improved consolidation was obtained by macaroni 
pressing and reblocking prior to extrusion, and nearly 
all lots submitted for gun trials were made in this 
way. Even so, a variable degree of porosity persisted, 
particularly in the larger granulations, with the result 
that succeeding batches made under apparently iden- 
tical conditions varied as much as 15^ in quickness. 
This factor probably accounts for the failure of several 
lots to meet ballistic specifications and must be rem- 
edied in future research. 

Basic lead carbonate was incorporated in some of 
the more recent granulations as an experimental de- 
coppering agent, with the hope of replacing the conven- 
tional lead foil. 

Four press cxjdosions occurred in the pilot ])lant, 
all of which were believed due to compression of ace- 
tone-air pockets. One was violent enough to blow out 
the extrusion die and remove the building roof, but 
in no case was the press cylinder ruptured. The bar- 
ricades served to prevent personal injuries. 

In July 1945, the Navy requested facilities for Al- 
banite manufacture at a rate of 4,000,000 lb per 
month. On the basis of equipment capacities deter- 
mined at the DINA and Albanite pilot plants, plans 
were laid to make DINA at Holston Ordnance Works 
and the propellant at Indiana Ordnance Works. The 
end of the war interrupted the program at the de- 
sign stage. 

It has so far been demonstrated that nitroguanidine 
propellants are thermally and ballistically sound where 
flash and erosion are important considerations. Time 
now being available for more extensive research, the 
Albanite formula should be reviewed with emphasis 
on reproducibility of burning rate. The nitroguanidine 
used up to date is now known to be relatively coarse 
by modern British standards, and a smaller crystal 


V)Ni'ii>i'.\'ri,MJ 


no 


PROPELLANTS 


size may improve consolidation of the colloid. A plas- 
ticizer better than the DINA-dihutyl phthalate com- 
bination may exist hntyl NI'IXA and certain related 
explosives are known to he more soluble in nitrocel- 
lulose than is DINA, and diethylene glycol dinitrate 
deserves evaluation. Surface active agents might be 
of considerable help. Less promising are changes in 
type of nitrocellulose or volatile solvent. It is intended 
to carry on the work under Navy auspices. 

68 RDX POWDERS^ 

The problem of improved gun propellants was up 
for discussion soon after the formation of the National 
Defense Research Committee. Both military and com- 
mercial propellants in this country had for decades 
used nitrocellulose or nitrocellulose-nitroglycerin mix- 
tures as their principal explosive ingredients. It seemed 
probable that other materials with explosive potential 
could be used to advantage, and the investigation of 
new gun propellants was, therefore, made a part of the 
work of the Explosives Research Laboratory.®^ Since 
Burnside Laboratory, as the smokeless powder research 
laboratory of the du Pont Company, had equipment 
for and experience in this kind of work, a contract was 
negotiated to cover the study of propellants containing 
crystalline high explosives.®^ 

While existing facilities were being modified so that 
experimental batches could he made safely on a 10-lh 
scale, the Explosives Research Laboratory examined 
a variety of propellent compositions on a 1-lb scale. 
The immediate goal of the investigation was to develop 
propellants capable of giving higher velocities than 
existing powders without exceeding permissible gun 
pressures and having as favorable flash, smoke, and 
erosion characteristics as possible. Calculations were 
made both at the Explosives Research Laboratory and 
at Burnside Laboratory for the selection of ingredi- 
ents which could be used to this end. The calculations 
at Burnside were based on IlirschfeldeEs thermochem- 
ical work carried out for NDRC Division 1.®^ 

The computations indicated that a combination of 
a high explosive with a strong deterrent would result 
in a powder of high potential with a relatively low 
adiabatic flame temperature. The latter is conducive 
to low gun erosion and reduced tendency toward muzzle 
flash. An investigation of explosives including TNT, 
PETN, DINA, RDX, tetryl, picrates, nitroguanidine, 
nitrocellulose, and numerous less familiar explosives, 
revealed RDX to possess the greatest thermochemical 

'T'his section is based on information supplied by W. F. 
Jackson. 


advantage. From a long list of deterrents, butyl stea- 
rate was selected as the most promising. 

A propellent composition for cannon was then for- 
mulated, using RDX and butyl stearate with nitro- 
cellulose as a binder to permit granulating. It was this 
type of composition which was investigated for ballis- 
tic, physical, and chemical properties. 

It was obvious from the variety of ballistic prob- 
lems involved that a single composition could not sat- 
isfy all the requirements in existing guns. A high- 
velocity cannon powder could not be flashless nor would 
it be suitable for rifles. Accordingly, adjustments had 
to be made in the composition to conform with the 
properties desired. The proportion of deterrent had 
to be lowered substantially in order to obtain sufficient 
potential for rifle powder. This permitted such small 
quantities of butyl stearate in the composition that 
dil)utyl tartrate or triacetin was substituted in rifle 
compositions to assure adequate plasticization. Five 
compositions received particular attention: CCl, a 
flashless cannon powder with normal ballistics and re- 
duced erosion; CC2, a high-velocity cannon powder 
with normal flash and erosion; CRl, a flashless rifle 
powder with reduced smoke, normal ballistics, and 
reduced erosion; CR‘J, a high-velocity rifle powder 
with normal erosion; CR3, a super- velocity rifle pow- 
der with increased erosion. The basic formula of each 
is given in the following tabulation : 



CCl 

CC 2 

CRl 

CR 2 

CR3 

Nitrocellulose (12,6% N) 

37.5 

36.5 

47.0 

50.0 

36.5 

RDX 

50.0 

53.0 

47.5 

45.0 

60.0 

Diphenylamine 

0.5 

0.5 

0.5 

0.5 

0.5 

Butyl stearate 

12.0 

10.0 

5.5 

• . . 

• . . 

Dibutyl tartrate 

Triacetin 




4.5 

*3.0 

K 2 SO 4 (added) 




0.7 

0.7 


The rifle powders were ordinarily coated with dini- 
trotoluene in varying amounts in accordance with the 
ballistics desired. 

Granulations were prepared for trial in a number 
of guns, including .50 caliber, .60 caliber, 20 mm T31, 
40 mm Army, 40 mm Navy, 75 mm Model 1897, 76 
mm Ml, 3-in. M5, Navy 3-in./50, 90 mm Ml, and 
Navy 5-in./38. The results of early trials were en- 
couraging.®® For example, it was possible with the CC2 
composition to increase the muzzle velocity of medium- 
caliber cannon about 100 fps with no increase in max- 
imum gun pressure beyond that obtained with the 
current single-base Service propellants. On the 
strength of these observations, considerable effort was 
put forth to adapt the manufacturing process to avail- 




STUDIES OF NITROCELLULOSE 


111 


able single-base powder facilities. The du Pont Mil- 
itary Explosives Division, with the cooperation of 
Eastern Laboratory, engineered the production of a 
30,000-lb batch of RDX of suitable fineness, desen- 
sitized with butyl stearate. The Division 8 propellant 
pilot plant at Burnside Laboratory studied the powder 
granulating process in full-scale equipment. 

Manufacturing details were satisfactorily worked 
out, and the propellants were found to be acecptable 
with respect to erosion, flash, and smoke characteris- 
tics, mechanical grain strength, explosive sensitivity 
to sliock, hygroscopicity, chemical stability, and vola- 
tility,®*’ but they suffered from one serious defect: the 
ballistic uniformity was poor. Velocity variations in 
nearly all weapons were far in excess of those observed 
with the conventional Ml, M2, or M6 compositions. 
In rifles, indications were that the uniformity could 
be made acceptable by adding extra igniter. This would 
probably require redesigning the case in many in- 
stances to accommodate a larger primer. In cannon, 
increased ignition was tried without success. It is 
probable that lack of ballistic uniformity in cannon is 
a result of the inherent progressive burning character 
of these compositions. An unusual sensitivity of burn- 
ing rate to changes of pressure at a few thousand psi 
was observed in closed- vessel tests of the KDX powders. 

Further work with RDX as a powder ingredient 
would call for fairly drastic revisions in the formula- 
tion. The ballistic advantages which would follow a 
satisfactory solution to the uniformity problem would 
repay considerable effort. 

69 STUDIES OF NITROCELLULOSE'" 

Under the sponsorship of Division 8 a number of 
investigations of nitrocellulose were undertaken. The 
two earliest were nonexperimental surveys on the use 
of wood cellulose nitrates for munitions,®^ and on the 
conversion of nitrocellulose to smokeless powder.®® An- 
other group of studies dealt with the mechanism of 
gelatinization and solution of nitrocellulose.®®'^®^ Still 
another group of studies was made at the California 
Institute of Technology.^®^*'®® These studies will be 
considered under six separate headings. 

6.9.1 Preparation of Samples of 

Nitrocellulose 

In connection with studies of the nitrocellulose in 
smokeless powder, it is frequently necessary to extract 

“This section is based on a summary written by Richard M. 
Noyes of the studies made at the California Institute of 
Technology. 


the other constituents, and to free the residue from 
moisture and extracting solvent. The procedures cur- 
rently employed for such separations arc discussed in 
Section 6.11.1 in connection with the determination 
of nitrocellulose in smokeless powder. Unfortunately 
it was found that, although these procedures are sat- 
isfactory for the determination of the percentage of 
nitrocellulose in smokeless powder, they frequently 
caused significant alterations in some of the properties 
of the nitrocellulose. 

x\l though no thoroughly satisfactory procedure has 
been developed for obtaining the nitrocellulose from 
a smokeless powder in a form suitable for further 
study, it has been found that uncolloided water-wet 
nitrocellulose can be dried either by vacuum desicca- 
tion at room temperature, or by heating at 70 C. Ex- 
periments at the California Institute of Technology 
indicated that dry nitrocellulose could be heated at 
70 C for as long as 100 hours without any detectable 
change in its properties, but that slow degradation 
occurred during the same period at 100 

6.9.2 Fractionation of Nitrocellulose 

In connection with studies of smokeless powder of 
unknown composition, it was often desirable to deter- 
mine the properties of the component nitrocelluloses 
which composed the blend used in the preparation of 
the powder. Therefore studies were made of procedures 
for the fractionation of nitrocellulose blends prepared 
from components having distinctly different percent- 
ages of nitrogen; no serious attempt was made in 
these experiments to extend these studies to the frac- 
tionation of unblended nitrocelluloses. 

Several nitrocelluloses prepared by blending known 
amounts of materials containing 12.6 and 13.4^ of 
nitrogen were fractionated into what appeared to be 
their original components by partial solution in 2/1 
ether-alcohol at 25 C.^®® The same procedure was used 
to study the properties of the component nitrocellu- 
loses in several captured German propellants,^®® but it 
was found that the nitrocelluloses in J apanese propel- 
lants could be fractionated more satisfactorily with 
the use of methanol.^®’' 

^ ^ ^ Chemical Characterization of 
Nitrocellulose 

The chief method employed for the chemical char- 
acterization of nitrocellulose is the determination of 
nitrogen; procedures for this determination are dis- 
cuseed in Section 6.11.1. 

Several observations have led to the conclusion that 


tPUFIDENTTATTi 


112 


PROPELLANTS 


nitrocellulose may not always be sufficiently charac- 
terized by nitrogen content and viscosity alone. Some 
attempts were consequently made to establish the pres- 
ence of groups other than nitrate and hydroxyl. Pre- 
liminary experiments failed to indicate detectable 
amounts of aldehyde groups in the nitrocelluloses in- 
vestigated, and lack of time prevented further studies 
along this line. 

6.9.4 Investigations of Molecular Weight 
and Molecular Weight Distribution 
in Nitrocellulose 

Several procedures are available for determining 
the average molecular weights of linear polymers like 
nitrocellulose. Of these procedures, measurements of 
osmotic pressure, of viscosity, and of light scattering 
were selected as the most promising, and studies of 
these techniques were made. 

1. Measurements of osmotic pressure. Procedures 
were developed for determining the number-average 
molecular weights of nitrocelluloses by means of meas- 
urements of osmotic pressure. These procedures appear 
to be quite satisfactory for tbe study of nitrocelluloses 
in double-base powders. 

2. Measurements of viscosity. Viscosimetric pro- 
cedures are those most frequently employed for studies 
of the molecular weight of nitrocellulose. Most com- 
mercial procedures involve only the purely empirical 
correlation of the properties of nitrocelluloses in terms 
of the viscosities of concentrated solutions prepared 
from them. Since the results of measurements on these 
concentrated solutions cannot be used to calculate the 
molecular weights of the solute nitrocelluloses, most of 
the studies at the California Institute of Technology 
wei’e made on dilute solutions of nitrocellulose. A few 
studies of concentrated solutions were also made in 
order to facilitate the comparison of measurements 
on dilute solutions with measurements by standard 
commercial procedures. 

The viscosities of dilute solutions of nitrocellulose 
in butyl acetate and in acetone were measured with 
capillary viscometers, and the results of these meas- 
urements were used to calculate weight-average molec- 
ular weights. Since molecular weights obtained by 
this procedure are only relative, it was necessary to 
obtain an absolute calibration by means of measure- 
ments on samples of known molecular weight. This 
calibration was effected by means of osmometric and 
viscosimetric measurements on carefully fractionated 
sam])les^®® wbicb were believed to be molecularly 
homogeneous. 


Measurements of viscosity on commercial nitro- 
celluloses are customarily made by means of a falling- 
ball viscometer on 10% solutions in 10/90 alcobol- 
acetone/^’® the results of these measurements are re- 
ported in Hercules seconds. This procedure requires 
a 20-g sample of nitrocellulose, and the precision 
claimed is only zh 3.8 per cent.^^^ A modified capillary- 
type viscometer by means of wbich measurements can 
be made with the use of only one gram of nitrocellulose 
was developed at the Cbilifornia Institute of Tech- 
nology.“^ This viscometer is satisfactorily precise for 
the measurement of viscosities of concentrated solu- 
tions, and the results can be converted to Hercules 
seconds by the use of a factor. 

An attempt was made to extend to higher concen- 
trations the results of viscosity measurements on dilute 
solutions of nitrocellulose in butyl acetate. These stud- 
ies were discontinued because the viscosities of the 
concentrated solutions were found to be extremely sen- 
sitive to traces of moisture. The viscosity of a 5.50% 
solution of nitrocellulose in anhydrous butyl acetate is 
six times the viscosity of a solution of the same con- 
centration prepared with butyl ace-tate saturated with 
water at 25 This and other observations indicated 
the necessity for great care in the use of pure solvents 
in viscosity studies. 

Viscosities of several nitrocelluloses were measured 
both in dilute solutions in butyl acetate, and in con- 
centrated solutions in alcohol-acetone, and the results 
were used to prepare a graph for estimating the vis- 
cosity of a nitrocellulose in Hercules seconds from the 
]‘esult of a viscosity measiiremeid on a dilute solu- 
tion in butyl acetate. 

3. jSI easurements of light scaltering. Apparatus was 
developed at the California Institute of Technology 
for determining the molecular weights of nitrocellu- 
loses by means of measurements of the light scattered 
at 90 degrees from the incident beam. The procedure 
usually gave results of the right order of magnitude, 
but more developmental work is needed before light 
scattering can be considered a reliable tool for meas- 
uring the molecular weight of nitrocellulose. 

4. Studies of the molecular heterogeneity of nitro- 
cellulose. The molecular heterogeneities of several ni- 
trocelluloses were studied. The ratio of weight-average 
to number-average molecular weight, determined by 
viscosity and osmotic pressure measurements, respec- 
tively, was taken as a measure of heterogeneity. This 
ratio is unity for homogeneous material and increases 
with increasing heterogeneity. The value of the ratio 
was found to be slightly less than 2 for nitrocelluloses 


PREPARATION AND PROPERTIES OF SOLVENTLESS DOUBLE-BASE POWDER 


113 


prepared from cotton linters but was about 2.5 for 
nitrocelluloses prepared from wood pulp ; it is hence 
concluded that the nitrocelluloses prepared from wood 
pulp are molecularly more heterogeneous than those 
from cotton linters. 

X-Ray Studies of Nitrocellulose 

X-ray diffraction ])hotogra})hs wore used to study 
the degrees of orientation and gelatinization in vari- 
ous smokeless powders. 

X-ray studies of mixtures of nitrocellulose with 
diethyl phthalate and with dil)utyl phthalate indi- 
eated the formation of compounds with these plas- 
ticizers.^^'”^ 

^ Studies of Artificially Aged Powders 

The techniques described in the preceding sections 
were used at the California histitute of Technology 
to study the changes which occur in the nitrocellulose 
in smokeless powder during accelerated aging at ele- 
vated temperatures. These studies indicated that the 
degradation of nitrocellulose in smokeless powder is 
very complex. In most of the douhle-base powders that 
were heated, a part of the nitrocellulose became in- 
soluble in the customary solvents. The nature of this 
insoluble material was not established, but it was 
suspected of being a three-dimensional polymer formed 
by some sort of cross-linking between nitrocellulose 
molecules. 

6.10 PREPARATION AND PROPERTIES OF 
SMALL BATCHES OF SOLVENTLESS 
DOUBLE-BASE POWDER" 

Introduction 

Beginning in July 1942, a comprehensive study of 
the relationships between the composition and prop- 
erties of double-base powders was earried on at the 
California Institute of Technology under OSRD Con- 
tract OEMsr-702 (July 1 to Decemher 31, 1942) and 
OSRD Contract OEMsr-881 (January 1, 1943 to 
December 31, 1945). An essential tool for this study 
was the equipment which was developed for the 
preparation by a slurry method of four-gram batches 
of rolled solventless sheet powder,^ and sixty-gram 
batches of solventless extruded powder.^^^ 

The equipment for the preparation of four-gram 
batches of rolled sheet powder is especially suitable 

*^This section is taken from a report prepared by A. O. 
Dekker. 


for preliminary tevsts of new compositions. Small 
samples of highly experimental powders which might 
be too hazardous to prepare in larger quantity can 
be prepared Avitli relatively little hazard for small- 
scale tests, or a wide range of compositions may be 
quickly surveyed by the preparation of a great many 
powders of related composition which can then be 
examined by various means in order to select those 
most suitable for preparation on a larger scale. 

Powders which are to be subjected to surveillance 
tests, measurements of linear burning rates, or de- 
terminations of physical properties, must be prepared 
in larger lots and in quantities sufficient for extru- 
sion. For this purpose a laboratory was constructed 
for the mixing, rolling, and extrusion of sixty-gram 
batches of solventless double-base powder. 

These two sets of equipment made it possible to 
prepare quickly and conveniently a great many pow- 
ders without which many investigations of propel- 
lants would have been impossible; for example, it 
was feasible to prepare batches of powder which con- 
tained no stabilizer or which contained substances 
which might destabilize the powder. 

In the following sections there are briefly 
described the equipment for preparing small batches 
of powder and the application of this equipment to 
studies of the stability, burning rate, and physical 
properties of standard, new, and foreign propellants. 

6.10 2 Equipment for the Preparation of 
Small Batches of Solventless 
Double -Base Powders 

The equipment which was developed for mixing 
slurries, the one-inch rolling mill which was de- 
signed for rolling four-gram batches of powder, the 
experimental rubber-rolling mill which was adapted 
for rolling sixty-gram batches, the one-inch press 
which was designed to extrude the rolled sheet pow- 
der, and the laboratory in which this work was done 
are described below. 

The Laboratory 

Figure 3 is a plan of the laboratory in which the 
small batches of solventless powder were prepared. 
Steam, compressed air, hot and cold water, circulat- 
ing hot water (190 F), and explosion-proof elec- 
trical outlets were supplied at several convenient 
places in the laboratory. Circulating hot water of 
constant temperature was supplied from a thermostat- 
ically controlled tank from which hot water was 


(('oxriiiiTvnTn 


114 


PROPELLANTS 



pumped to the far end of the laboratory by means of 
a centrifugal pump and was returned to the tank. 
Apparatus which was to be heated by this circulating 
water was connected in parallel with the supply and 
return lines of the system. 

Ventilation was provided by several air ejectors 
which exhausted noxious or explosive vapors at their 
points of origin. 

Emergency showers and fire extinguishers were 
])rovided at convenient places throughout the labora- 
tory. Separate magazines for high explosives, nitro- 
cellulose, and douhle-hase powder Avere situated at 
appropriate distances from the laboratory. 

Mixing the Slurry 

Slurries for four-gram batches of powder were 
mixed in small glass beakers which, together with 
air-driven stirrers and a balance, Avere mounted be- 
hind a steel barricade. 

Figure 4 is a photograph of one of the tAVo nearly 
identical mixers for preparing slurries for sixty-gram 
hatches of poAvder; this apparatus Avas designed so 
that practically all operations Avere controlled from 
a panel in another room Avhich Avas separated from 
the first by an 8-in. concrete Avail. Mirrors permitted 
the operator to observe the apparatus from the door 
Avithout exposure. At no time Avas the operator ex- 
])osed to high explosives Avhich Avere at elevated tem- 
])eratures or in more than gentle motion. 

4die apparatus is best described by outlining the 


method of its operation for the preparation of a 
nitroglycerin poAvder. A brass cup containing Avater, 
and provided Avith a coil of copper tubing for tem- 
perature control Avas mounted on the piston rod of 
a hydraulic cylinder. With the piston at its loAver 
position a beaker containing a suitable quantity of a 
10% solution of nitroglycerin in alcohol Avas clamped 
in the cup. Water at 60 C Avas passed through the 
coil in the cup and a brisk stream of filtered air Avas 
directed upon the surface of the solution in the 
beaker. A hood directly above the mixer removed the 
vapors. When all the alcohol had evaporated, cold 



Figure 4. Apparatus for mixing sixty-gram batches of 
double-base powder by a slurry process. 


Con FI DKM’i Alfj 


PREPARATION AND PROPERTIES OF SOLVENTLESS DOLBLE-RASE POWDER 


115 



ALONG ISOMETRIC AXES 

Figure 5. Small powder-rolling mill. 


AA Iron casting; base of rolls. 

BB Interchangeable spur gears. 

.4 Roll (stainless steel collar). 

B Roll shaft (stainless steel) . 

C Central hole in roll shaft, for water circulation. 

D Guide; determines width of powder sheet and keeps powder away 
from bearings. 

E Doctor knife for removal of sheet powder from rolls. 

F Axle for rotation of block which supports right-hand roll. 

G Set-screw for determining space between the rolls. 

II Roll-shaft bearing (bronze). 

I Lubrication fitting; grease inlet. 

J Grease hole. 

K Gaskets of “Garlock” packing material (asbestos impregnated with 
graphite). 


L Rear water-circulation bushing (non-rotating). 

M Forward water-circulation bushing (non-rotating). 

N One of the screws which tighten the rear bearings. 

O One of the two screws which tighten the forward bearings. 

P Thermometer well. 

Q Water-inlet pipe for right-hand roll. 

R Flexible metal bellows. 

»S Outlet pipe from right-hand roll. 

T Forw'ard water chamber. 

U Partition. 

V Water-inlet pipe to rear water chamber and to left-hand roll 
IF Rear water chamber. 

X Inlet to left-hand roll. 

Y Outlet from left-hand roll. 

Z Water-outlet pipe, both rolls. 


^)]gJIT)K>rTiA.Ll 


116 


PROPELLANTS 


water was })asse(l tlir()u»*li the eu})i)er eoil, a meas- 
ured amount oi' metliyleelliilose dispersed in water 
was added to the pure nitro^lveerin by remote con- 
trol, and the cup and beaker were raised by the 
hydraulic cylinder to the upper position where an 
air-driven stirrer emulsilied the nitroglycerin and 
water. Xitrocellulose, plasticizer, and stabilizer were 
then added and the stirring was resumed for 35 
minutes. 

Slurries containing crystalline explosive plasticizers 
such as DIXA had to he heated above the melting point 
of the ex})losive })lasticizer during the mixing. 

liOLLlXG THE SlUUKIES 

One-inch UolJing Mill. The small powder-rolling 
mill which was designed and constructed in the lab- 
oratories of the California Institute of Technology, 
is shown in Figures 5, 6, and T. Figui'e 5 is a cutaway 
isometric drawing of the mill excluding the motor 
and worm drive. This drawing shows the details of 
construction, the bearings and lubrication system, 
and the water circulation system. 

The rolls, which were 1 in. in diameter and IVs in. 
long, were driven by a Vs-hp explosion-proof electric 
motor through a worm gear and a set of interchange- 
able reducing gears; they Avere mounted on a holloAV 



Figure 6. Small powder-rolling mill, complete with 
explosion-proof motor and worm gear. 


cast-iron base AA by means of Avhich they Avere sup- 
plied Avith circulating steam or hot Avater for tem- 
perature control. The hot Avater or steam Avas caused 
to hoAv through the steel shafts AAdiich carried the 
rolls, ddie spacing betAveen the rolls could be ad- 
justed to any value up to about 0.014 in. by means 
of an adjustable set-screAV G. The fast roll Avas usually 
driven at a speed of 46.1 rpm and the ratio of the 
speeds of the tAv^o rolls aauis usually 1.29. 


Tlic lai’ge angle of nip of tlic 1-in. rolls caused 
ditlicullies Avhich are not eiu'ountercd Avith larger 
lolls. If proper prei-autions Avere not taken the stock 
piled up in the bite of the rolls and did not form a 
sheet. This difficulty could be avoided by adding the 




Figure 7. Small jioAA'der-rolling mill, close-up aucav. 


stock sloAvly and by carefully controlling the other 
factors Avhich affect the rolling characteristics of the 
slurry. 

Three-T nch Rolling Mill. The laboratory rubber- 
rolling mill (Figure 8) AA^as purchased from William 
E. Thropp and Sons. It consisted of tAvo horizontal 
heated rolls, 3 in. in diameter and 8 in. long, Avhich 
Avere driven by a 2-hp, 3-phase, explosion-proof motor 
equiiiped Avith a magnetic brake. The gears on the 
front and rear rolls AA*ere exchanged so that the front 
roll AA'ould revolve faster than the rear roll. The front 
roll, AAdiich Avas adjustable for different spacings be- 
tAveen the rolls, revolved at 26.9 rpm ; the ratio of 
the speeds of the rolls Avas 1.40. 

The rolls, AAdiich Avere holloAv, aaxwc connected 
through suitable valves Avith the laboratory circulat- 
ing hot Avater system, Avith the cold Avater and steam 
lines, and Avith a heat exchanger, so that the tem- 
perature could he regulated as desired. When the 
proper temperature Avas reached the rolls Avere usually 
spaced at 0.010 in., and the filtered slurry Avas re- 
duced to a finely divided voluminous mass AAdiich AA^as 
gradually added to the rolls over a period of about 
half a minute to tAA'o minutes, depending on the be- 
havior of the stock on the rolls. The poAvder Avas then 
prerolled for one minute to remove moisture and to 
initiate plasticization. The partially colloided sheet 
Avas bookfolded and returned to the rolls for an addi- 
tional three minutes, during Avhich the sheet Avas 
removed four or five times, folded into several book- 



PKErARATION AND PROPERTIES OF SOLVENTLESS DOUBLE-BASE POWDER 


117 



Figure 8. Powder-rolling mill, complete with explosion- 
liroof motor and magnetic brake. 


folds, and returned to the rolls. Some powders had 
to be rolled for a longer time as a result of the specific 
composition or of the condition of the surfaces of 
the rolls. It was sometimes necessary to reduce the 
spacing of the rolls in order to plasticize Avliite specks 
of incompletely incorporated nitrocellulose. Salts and 
carbon black Avere added ‘early in this three-niinntc 
period. 

The sheets obtained Avere about (1 in. Avide, 19 in. 
long, and of a thickness AAdiich Avas of the order of 
0.025 in., but AAdiich depended on the quantity of 
poAA'der Avhich could be conveniently rolled into a 
sheet. 

Extruding the Polled Sheet Poavder 

Figure 9 is a draAving in cross section of the barrel 
and piston of the 1-in. extrusion press, the design 
of AAdiich is based on that of the small 0.5-in. press 
constructed by Section 5.'’ The barrel of the press, 
Avhich Avas machined from heat-treated alloy steel, 
Avas mounted vertically and surrounded by a heavy 
copper heating jacket AAdiich contained a helix-shaped 
Avater channel; the loAA^er end of the cylinder was 
threaded to accommodate the die for extrusion. The 
1-in. piston, machined from alloy steel and provided 
Avith bronze sleeves, Avas moved by a 10-ton Porto- 
PoAver hydraulic ram (BlackhaAvk Manufacturing 


Company) Avhich Avas mounied above and connected 
to the extrusion cylinder. Provision Avas made for 
the evacuation of the press through the piston. A 
valve in the end of the piston closed the vacuum con- 
nection automatically Avhen the piston Avas pressed 
against the poAvder. A second hydraulic cylinder, 
mounted above the Porto-PoAver ram and connected 
to the extrusion piston by four circumferentially 
spaced connecting rods, AvithdrcAv the extrusion piston 
at the end of its stroke. The tAA^o hydraulic cylinders 



Avere connected by means of a suitable system of 
vah’es to a hand-operated pump (BlackhaAvk Model 
P-76), to a reservoir, and to a small-capacity ac- 
cumulator. 

Dies for the extrusion of cylindrical rods of poAV- 
der of Yio-} % 2 -^ %g-> and %-in. diameter, and 
spider and mandrels for the extrusion of tubular grains 
Avith the dimensions %x%(j in., %2^%2 bi., and 
%2^%4 bi. Avere prepared according to the meth- 


"Contract OEM.sr-418.ii®^ 




118 


PROPELLANTS 


uds of design wliieli were develo})ed by Section 5 .p 

Tlie 1-in. press proved to be very satisfactory with 
the exception of the hydranlic system. A more easily 
controlled and operated hydranlic system which 
won Id deliver a more nearly constant pressure prob- 
ably could be assembled from a double-acting cylinder 
and a motor-driven pump which can be purchased 
on the market, but this hand-operated pump and the 
two single-acting cylinders were fairly satisfactory. 

Preliminary to extrusion the sheet obtained from 
the 3-in. rolls was formed into a tight carpet roll 
6 in. long and nearly an inch in diameter. The carpet 
roll was preheated at a suitable temperature for 20 
minutes and then placed in the press at the same 
temperature. The press was evacuated for two min- 
utes at 4 mm of mercury pressure and the extrusion 
was started. The pressure prevailing during the ex- 
trusion was of a magnitude such that the rate of 
extrusion of a quarter-inch grain was of the order 
of an inch per second, and correspondingly higher 
pressures and rates were used for smaller granula- 
tions; no effort was made to obtain any particular 
extrusion rate. 

Discussion of the PEOCEuuPtE for the 
Preparation of Small Batches of Powder 

Ejfect of yariatio7is in the Mixing and Rolling 
Procedures. An extensive series of experiments was 
carried out in order to determine the extent to which 
the properties of four-gram batches of powder were 
affected by variations in the procedure such as those 
which were to be expected under ordinary operating 
conditions. The time and violence of mixing the 
slurry, the moisture content of the slurry at the time 
of placing it on the rolls, the time and temperature 
of rolling on the 1-in. rolls, and many other variables 
were investigated. The variations had either no effect 
or an insignificantly small effect on the rolling char- 
acteristics of the slurry, and on the qualitative physical 
properties, the pll value, and the vacuum stability 
behavior of the powders. 

Comparison of Balch Formulas and Aiialgses. 
Many four-gram and sixty-gram batches of powder 
were prepared and analyzed in order to determine 
the precision with which the compositions of the 
experimental powders could be controlled. These 
analyses permitted the development of precise pro- 
cedures for the preparation of powders, so that their 
compositions were generally closer to the specifica- 


tions than was the practice with production lots of 
powder. 

Cotn parison of Poicders irith ProdacUon Lois. 
Iji a])pearance, qualitative physical properties, and 
burning rate, the sixty-gram batches of powder could 
not be distinguished from production lots of iden- 
tical composition. 

In stability there seemed to be no significant 
differences between the small batches and production 
lots except for diphenylamine-stabilized powders. 
For example, without exception the centralite-stabi- 
lized powders prepared at the (hdifornia Institute of 
Technology, Avhen stored at elevated temperatures, 
were depleted of centralite at rates which could have 
been predicted roughly from the rates of depletion 
in production lots of similar composition.^^® On the 
other hand, also Avithout exception, the diphenyl- 
amine-stabilized poAvders, AAdiich Avere prepared in 
this laboratory, AA^ere depleted of diphenylaniine more 
than tAvice as rapidly as ballistites AA'hich AA^ere pre- 
pared in production lots.^^® 

Investigation shoAved that this anomalous behavior 
of the diphenylaniine poAvders Avas to be ascribed only 
to the operations of rolling the poAvder on the 3-in. 
rolls and extruding the poAA'der from the 1-in. press 
and not to the mixing of the slurry or to the purity 
of the components of the slurry. It is possible that 
this behavior AA'as due to air taken up by the poAvder 
during rolling and extrusion. 

Quanta y of Production. One man Avas able to mix 
and roll 10 four-gram hatches of different composi- 
tions in three eight-hour days. This output could 
be doubled if the laboratory Avere in a plant Avhere 
nitroglycerin is manufactured so that pure nitro- 
glycerin could be obtained AAuthout the time-consum- 
ing evaporation of alcohol from a 10^ solution. 

Tavo men Avere able to mix, roll, and extrude about 
20 or 25 sixty-gram batches of poAvder in five eight- 
hour days; hoAA^ever, if the compositions AA’ere not 
very closely related, so that the rolling or extrusion 
conditions had to be changed for each batch, the 
number of batches produced in this time Avas only a 
dozen or so. Here again the output could be doubled 
if pure nitroglycerin rather than a solution Avere 
available. Moreover, a different plan for the building 
and for the location of operations in it Avould permit 
perhaps a 30% increase in output, even though only 
nitroglycerin solutions AA^ere available; Avith the pres- 
ent arrangement it Avas not considered safe to permit 
poAvders to be rolled at the same time that other poAV- 
ders Avere being mixed in the adjoining room. 


pContract OEMsr-IlS.^^^*’ 


1’HEPAHATION AND PROPERTIES OF SOEVENTLESS DOUBLE-RASE POWDER 


119 


6.10.3 Application of the Equipment to 
Studies of Smokeless Powder 

The equipment for the preparation of four-gram 
batches Avas used to prepare about 700 batches of 
poAvder for studies of various plasticizers and sta- 
bilizers, for studies relating to the formulation of 
neAV propellants, and for investigation of foreign 
propellants. The equipment for the preparation of 
sixty-gram batches Avas used to prepare more than 
500 batches of poAvder for similar studies and for use 
in determinations of the linear burning rate and 
elastic modulus of propellants under compression. 

The slurry mixer, 3-in. rolls, and 1-in. press, de- 
scribed in the preceding sections, Avere not only use- 
ful but essential to the prosecution of the AV'ork on 
this contract. The more significant types of investiga- 
tions AA'hich Avere made Avith this equipment and Avith 
the smaller equipment are indicated very briefly in 
the folloAving sections. 

COMPAKISOX OF AArIOUS COMPOUNDS AS PlASTI- 
ClZEPvS IX SOLVFXTLESS POLLED ShEET PoAADER 

Noiiexplobive Plasticizers. The 1-in. rolls Avere 
originally intended for use in a study of the relative 
merits of a Avide variety of compounds as plasticizers 
of nitrocellulose in solventless poAvders. A description 
of the general procedure used in these investigations 
is given in the folloAving paragraphs, and a summary 
of the results obtained is presented in Table 3. 

All the poAvders Avere based on a ballistite com- 
position and contained neither salt nor coloring 
agent. Four-gram batches of poAvder containing 3 to 
5% of each plasticizer alone AA^ere mixed, the pOAV- 
ders Avere rolled on the 1-in. differential rolls at 
75 C by a standard procedure, and the length of time 
required for each mix to form a translucent sheet 
Avas note^ as a criterion of the rate of plasticization 
of the nitrocellulose. The finished sheets Avere ex- 
amined visually and Avere rubbed and flexed Avith the 
fingers; small pieces AA^ere pulled off and torn from 
the sheet to olfiain some indication of the toughness 
of the sheets. 

The results of studies of several series of plasti- 
cizers are summarized roughly in Table 3. Many of 
the 89 compounds listed Avere studied Avhile the tech- 
nique of rolling sheet poAvders on the 1-in. rolls Avas 
still being developed; the classification of these com- 
pounds is someAvhat uncertain, and they are marked 
Avith an asterisk to distinguish them from the com- 
pounds which have been studied more recently. 


Table 3. Tentative classification of various compounds 
as plasticizers of nitrocellulose in solventless rolled 
sheet poAvders.ii®32i 


Compounds which yield flexible sheet powders 


Group I 
Acetophenone* 

Allyl 2-nitro-2-methyli)ropyl 
maleate 
Butyl lactate* 

Butyl phthalyl butyl 
glycolate* 
Cyclohexanone * 

Dibutyl phthalate* 
Diethoxyethyl phthalate* 
Diethyloxanilide 
Diethyl phthalate 
Diethyl tartrate 
Di (2-nitro-2-methylpropyl) 
maleate 

Diphenylcarbamic anhydride 

Group II 
Acardite 

Acetyl tributyl citrate* 
Dimethoxyethyl phthalate 
Diphenyloxanilide 
N -Ethyl-N '-phenylurea f 


Diphenylformamide 
Diphenylurethane 
Ethyl centralite 
Ethylphenylf ormamide 

N-Ethyl-N-phenylurea 

Isophorone* 

Pentaerythritol diacetate 
dipropionate 

Pentaerythritol tetraacetate 
Phthalide 

o- and p-Toluene ethyl 
sulfonamides* 

o- and p-Toluene sulfonamides 

Triacetin 

Triethyl citrate* 


Methyl phthalyl ethyl glycolate 
Sucrose octaacetate 
Tetraphenylureaf 
Tricresyl phosphate 
Triphenylisocyanuric acid 


Compounds which yield stiff sheet powders 


Group III Compounds which yield poorly plasticized, 
weak, brittle sheet powders 
Dibutyl sebacate* Methyl abietate* 

Hexaphenylmelamine /3-Nerolin 

♦Studied during the preparation of the first 75 powders on the 1-in. rolls 
fSeveral days after rolling, the surfaces of sheets containing 4.25% of this 
compound exhibited microscopic crystals. 


E.vplosive Plasticizers. A qualitative comparison of 
the plasticizing actions of diethylene glycol dinitrate 
and nitroglycerin in ballistite JPH Avas made by 
means of the 3-in. rolls and 1-in. press.^^^ 

Sixty-gram batches of poAvders of the compositions 
shoAvn in Table 4 Avere mixed and rolled and then 
extruded through a 0.25-in. die. 

DEGN, Avhich softened the powder much more 
than nitroglycerin, is apparently best suited to the 
preparation of poAvders Avhich contain a larger per- 
centage of nitrocellulose. 

The tAAm poAvders prepared from pyrocotton seemed 
to be harder than those prepared from the blend of 
pyro- and guncotton. Preliminary quantitative meas- 
urements of the hardness of nitroglycerin powders 
Avith a testing machine (Section 6.13) indicated that 
this effect of the nitrogen content of the nitroeellulose 
Avas real. 

The study of the plasticization of poAvders by ex- 
plosive and nonexplosive plasticizers was better car- 
ried out on the sixty-gram scale than on the four- 
gram scale, because additional data were obtained 
during the extrusion and because quantitative deter- 


120 


PROPELLANTS 


Table 4. Composition and qualitative j)hysical i)rop- 
erties of powders containing nitroglycerin (NG) or 
diethylene glycol dinitrate (DEGN). 


a. Formula percentage composition 

Nitrocotton 


54.5 

Explosive plasticizer 


43.0 

Ethyl centralite 


1.00 

Potassium sulfate 


1.50 

Carbon black (added) 


0.10 

The types of nitrocotton and explosive plasticizer are 

listed below. 

Powder No. C-112 

C-113 

C-114 C-115 

Nitrocotton, Lot No. 5251 

10411 

5251 10411 

Per cent of N 12,55 

13.23 

12.55 13.23 

Viscosity (Hercules 

seconds) 10 

11 

10 11 

Explosive plasticizer NG 

NG 

DEGN DEGN 

b. Qualitative physical properties of grains 

extruded through a 

0.25-in. die 

Powder No. C-H2 

C-113 

C-114 C-115 

Extrusion pressure (psi) 6100 

4600 

3100 2300 

Average diameter(inch) 0.278 

0.272 

0.273 0.269 

Hardness Very 

Hard 

Soft Very 

hard 


soft 


minatioiis of the hardness and elastic modulus under 
compression could he made with the extruded 
powders. 

Relationship Between the Peoperties of the 
Nitrocellulose and the Strength of JPH-Type 
Ballistites 

As indicated in the preceding paragraphs, sixty- 
gram batches of potvder are suitable for studies of 
the relationship between the properties of the nitro- 
cellulose and the strength of the powder in whicli 
these nitrocelluloses are incorporated. In an inves- 
tigation which was designed to develop a new pro- 
pellant with greater physical strength than ballistite 
JPIT, 16 powders were prepared which were identical 
in composition except for the nitrocellulose which was 
used, and the hardness and elastic modulus under 
compression of each of these were to be determined. 
The compositions of these powders are shown in 
'Table 5. This type of investigation could be carried 
out more economically and expeditiously by the use 
of the laboratory for the preparation of small batches 
of powder than by use of a pilot plant in which 
batches of at least several hundred pounds are usu- 
ally made. 

Studies Which Relate to the Stability of 
])oui{le-Base Rowder 

The investigations carried out under OSRD Con- 
tract OEMsr-881 were largely concerned with the 
study of the stability and safe life of double-base 


Table 5. Formula percentage composition of JPH- 
type ballistites which contain different nitrocelluloses. 


Nitrocellulose, according to specifications below 54.5 


Nitroglycerin 43.0 

Ethyl centralite 1.00 

Potassium sulfate 1.50 

Carbon black (added) 0.10 


Description of Nitrocellulose 


A 


Powder Hercules 

No. Lot No. 

Nitrogen 
per cent 

Viscosity, 

Hercules 

seconds 

Type 

C-137 

5168 

12.60 

8 

Cotton 

C-138 

8432 

12.67 

8 

Wood 

C-139 

5250 

12.55 

15 

Cotton 

C-140 

5245 

12.52 

15 

Wood 

C-171 

2917 

11.89 

11.7 

Cotton 

C-172 

2733 

11.98 

6.0 

Cotton and wood 

C-173 

2936 

12.13 

1.0 

Cotton and wood 

C-174 

3293 

11.95 

0.49 

Cotton and wood 

C-175 

1087 

11.95 

0.04 

Wood 

C-211 

5247 

13.45 

11 

Cotton 

C-213 

2917 (27.25%) 

11.89 

11.7 

Cotton 


3323 (27.25%) 

12.08 

0.04 

Cotton and wood 

C-214 

3323 (15.6%) 

12.08 

0.04 

Cotton and wood 


5250 (38.9%) 

12.55 

14 

Cotton 

C-215 

2733 (30.5%) 

11.98 

6.0 

Cotton and wood 


5247 (24.0%) 

13.45 

11 

Cotton 

C-216 

2917 (30.0%) 

11.89 

11.7 

Cotton 


5247 (24.5%) 

13.45 

11 

Cotton 

C-217 

3234 (18.3%) 

10.96 

0.05 

Cotton 


5246 (36.2%) 

13.45 

13 

Cotton 

C-218 

1087 (37.1%) 

11.99 

0.04 

Wood- 


2465* (17.4%) 

13.96 

100 

Cotton 


*This lot was prepared at the Picatinny Arsenal. 


powders. In connection with these investigations, a 
vacunni stability test at HOC and a modified Taliani 
test at 110 C were developed for use with double-base 
powders (Section 6.12). These tests were applied 
to a study of the effects of a great variety of changes 
in composition upon the relative i‘ates of gas evolu- 
tion. Powders prepared in small batches in this lab- 
oratory provided the material from Avhich many data 
were obtained for investigation of relatioi'^hhips be- 
tween the composition and the stability of double- 
base powders. 

The apparatus for the preparation of sixty-gram 
batches of powder was more suitable than the smaller 
equipment, because forty-five-gram samples of the 
larger batches were available for surveillance tests 
and ten- to fifty-gram samples could be stored for 
determination of the rate of depletion of the sta- 
bilizer. In this way data could be obtained to test 
the validity of correlations between the long-time 
low-temperature tests, such as the standard surveil- 
lance test at 65.5 C, and the short-time high- tem- 
perature tests, such as the Taliani-type test. 


PREPARATION AND PROPERTIES OF SOLVENTLESS DOUBLE-BASE POWDER 


12J 


Tlio oquipnicnt Avas used to ])re|)are imAvders in 
wliieli ditl'erent ex})losives, nitrocelluloses, coloring 
agents, plasticizers, stabilizers, and various organic 
and inorganic compounds were incorporated, and the 
powders were investigated by means of the tests 
which have already been mentioned. 

For example, nine powders of JPH-type composi- 
tion were prepared, in Avhich the folloAving stabilizers 
or compounds Avere used respectivelA\ 


Xo stabilizer 
Ethyl centralite 
Diphenylformaiiiide 
Acardite 

Ethylphenyhirethane 


Diphenylurethane 

Carbazole 

iS-Xerolin 

Tetraphenyliirea 


Samples of the jwAvders Avere placed in surveillance 
at 05. o C and at 75 C, and vaciuini stability and 
Taliani tests AA'ere made on the other samples. 

As another example, poAvders containing as sta- 
bilizers those derivatives of diphenylamine or ethyl 
centralite AAdiich are formed during the decomposi- 
tion of the poAvder Avere prepared for use in studies 
of the kinetics of the reactions AA’hich are iiiA’olved in 
the decomposition of the poAAxler at 65, 71, or 75 C. 
For this purpose 14 ballistite-type poAvders contain- 
ing the folloAving respective stabilizers AA^ere prepared. 


Diphenylamine 

X-Xitrosodiphenylamine 

4-Xitrosodiphenylamine 

2-Xitrodiphenylamine 

4-Xitrodiphenylamine 

4,4'-Dinitrodiphenylainine 

2,4,4'-Trinitrodiphenylarnine 

2,2',4,4',6,6'-Hexanitrodi- 

phenylamine 


X-Xitroso-4-ni trodipheny la- 
mine 

Ethyl centralite 
4-Xitrocentralite 
X-Xitroso-X-ethylaniline 
X-Xitroso-4-nitro-X-ethyl- 
aniline 

4,4'-Dinitrocentralite 


The rates of transformation of these stabilizers at 
elevated temperatures AAere determined. 


IXAn>:STICTATIOXS OF THE LiXEAP EUPXIXG RaTES OF 

Ppopellext Poavdeks of Vapious Compositioxs 

The apparatus for the preparation of sixty-gram 
batches of poAvder played a necessary part in inves- 
tigations of the linear burning rates of propellent 
})OAvders^^^ AAdiich Avere carried out under OSPD Con- 
tract OEMsr-881. Every poAvder Avhose burning rate 
Avas to be determined had to be provided in a granu- 
lation suitable for use in the burning rate apparatus. 
Samples from production lots or pilot lots of Ameri- 
can poAvders, and samples of captured German and 
Japanese poAvders were reduced to % 2 -in. grains by 
use of tbe rolls and the press. PoAvders prepared from 
our oAAUi slurries Avere also extruded as grains. 

In addition to this function of supplying material 
in a suitable granulation, the laboratory made it pos- 


sible to carry out studies of the relationships be- 
tAveen the composition of poAvder and its burning 
characteristics. For example, it aatis reported^^^*^-^ 
that one of the neAV standard compositions for use in 
German rockets aatis the one listed in Table 6. 


Table 6. Percentage composition of German Einheits- 
pulver R 61 


Nitrocellulose (12.5 per cent nitrogen) 

59.8 

Diethylene gljcol dinitrate 

35.3 

Hydrocellulose 

1.50 

Ethylphenylurethane 

1.10 

Diphenylurethane 

0.80 

I. G. Wax E 

0.35 

Magnesium oxide 

0.20 

Potassium nitrate 

0.60 

Acardite 

0.30 


111 the absence of a captured sample of this com- 
position, a sixty-gram batch Avas prepared in Avhich 
Avas incorporated 0.10^ of graphite, AAdiile carnauba 
Avax Avas sidistituted for the I. G. AVax E. Measure- 
ment of the burning rates at various temperatures 
and pressures shoAved that this poAvder had a loAver 
temperature coefficient of the linear burning rate 
and a loAver pressure coefficient of the linear burning 
rate than any of the other poAvders containing diethyl- 
ene glycol dinitrate Aidiich Avere iiiA^estigated at the 
California Institute of Technology. To determine the 
cause of these superior burning properties, about 40 
additional poAvders Avere prepared in AAdiich various 
constituents Avere omitted or replaced by closely re- 
lated substances. By this means it Avas possible to 
shoAv^ that the combination of hydrocellulose and po- 
tassium nitrate (and, to a lesser extent, magnesium 
oxide) produced superior burning characteristics. It 
Avas also possible to sIioav that incorporation of these 
substances had little or no effect on ballistite but im- 
proved the burning characteristics of H-4 poAAuler. 
A study of this sort by means of 500-lb pilot-lot 
liatches Avould have been much more expensive and 
time-consuming. 

Fo u EIGX 1 huiPE ELAX TS 

As indicated in the preceding section, the equip- 
ment Avas useful in studying the linear burning rates 
of foreign propellants. Not only Avas it possible to in- 
vestigate the detailed features of the burning charac- 
teristics of captured foreign poAvders, but it Avas also 
])ossible to test the validity of quantitative analyses 
of these propellants. When the composition Avas de- 
termined by analysis, a sixty-gram batch of poAvder 
could be prepared for a comparison of its physical 


frWFTDKyfTAp 


122 


PROPELLANTS 


properties and burning characteristics with those of 
the foreign powder. 

New Propellants 

Some of the applications of the equipment for the 
preparation of small batches of powder to the devel- 
opment of new propellants are partly evident from 
the preceding sections on studies of plasticization, 
nitrocellulose, stability, and linear burning rates. 
In addition to the types of investigations which have 
already been indicated, several other series of ex- 
periments were made with a view to the formulation 
of new propellants. The results of two of these series 
are very briefly described in the following paragraphs. 

EDX and PETN Propellants. Powders of rela- 
tively high potential, in comparison with a JPH- 
type ballistite, were prepared in four-gram batches 
by the incorporation of RDX and PETN in a bal- 
listite-type binder. Powders containing as much as 
36% of PETN in a ballistite matrix, and with heats 
of explosion as much as 100 calories per gram higher 
than that of JPH, were prepared, and their qualita- 
tive physical properties were determined.^^® The 
sheets were fairly flexible, but contained small per- 
forations and, upon aging, crystals developed on the 
surfaces. The experiments were not continued. 

DINA Propellants. Because of the relatively high 
volatility of nitroglycerin, there was considerable in- 
terest in the development of new propellants which 
contain less volatile explosive plasticizers. For this 
work the 1-in. rolls provided a very convenient and 
economical method of determining whether or not 
projected compositions could be successfully colloided 
by solventless rolling, and for obtaining samples for 
qualitative comparisons. A comprehensive study of 
powders containing DINA, Fivonite, and methyl 
NENA was carried out with this equipment. Four- 
gram batches of more than fifty different composi- 
tions were prepared, qualitative observations were 
made of their physical properties, and some were 
tested in the vacuum stability apparatus.®^ Fivonite 
was found to be useful in relatively small quantities 
as a plasticizer for DINA powders; when used as 
the only explosive plasticizer in a powder, Fivonite 
yielded a slurry which could not be rolled. Methyl 
NENA offered no advantages over Fivonite as a plas- 
ticizer for DINA powders and had the disadvantage 
of being about as volatile as nitroglycerin.^^^ All the 
powders which had ballistic properties comparable 
to those of ballistite were supersaturated with respect 
to the explosive plasticizer, and this crystallized on 


the surface of the sheets on standing. As in Albanite 
gun propellants, it was by no means certain that the 
crystallization was a serious disadvantage, but this 
could only be determined by much more extensive 
investigations. 

6 11 THE ANALYSIS OF POWDERS** 

^ Chemical and Physical Methods 

The material presented in this section is pri- 
marily the result of work carried out at the Cali- 
fornia Institute of Technology under OSRD Con- 
tract OEMsr-881. It consists essentially of critical 
investigations of many of the standard methods cur- 
rently used for the determination of individual con- 
stituents of smokeless powders and of new or revised 
procedures which were developed for the analysis of 
new powders or for the attainment of greater pre- 
cision. In addition to these purely analytical prob- 
lems, studies have been made of the fractionation, 
molecular weight determination, and aging behavior 
of nitrocellulose; these studies are described in Sec- 
tion 6.9. 

The analytical investigations and procedures are 
grouped for discussion under the following headings : 

1. Procedures for the determination of nitrocel- 
lulose and for the estimation of the percentage of 
nitrogen in it. 

2. Procedures for the identification and quantita- 
tive estimation of nitric esters and nitro compounds. 

3. Procedures for the quantitative estimation of 
stabilizers and nonexplosive plasticizers. 

4. Procedures for the quantitative estimation of 
volatile and inorganic constituents. 

The application of chromatographic and spectro- 
photometric methods to problems of powder analysis 
is described in Section 6.11.2. 

Procedures for the determination of Nitrocel- 
lulose AND FOR the ESTIMATION OF THE 
Percentage of Nitrogen 

All analytical studies of nitrocellulose from powder 
are hampered by the difficulty of obtaining samples of 
nitrocellulose which are free from moisture and 
volatile solvents, and are in a form suitable for fur- 
ther study. Samples of commercial uncolloided water- 
wet nitrocellulose can be dried easily, either by mild 
heating or by vacuum desiccation, but material which 

‘‘This section is taken from a report submitted by Richard 
M. Noyes. 


THE ANALYSIS OF POWDERS 


123 


has been precipitated from dispersions in organic 
solvents can be dried only with difficulty and is ap- 
parently degraded by heat more easily than is un- 
treated nitrocellulose. 

Determination of NitroceUidose. Nitrocellulose in 
smokeless powder is customarily determined in the 
residue remaining after extraction of the sample 
with ether or metlwlene chloride. The solvent re- 
tained in the residue after extraction cannot be re- 
moved by gentle heating or evacuation, but two pro- 
cedures are available for obtaining the nitroc-ellulose 
in a form suitable for weighing. 

The usual procedure, called the Xaval Powder 
Factory procedure, is that embodied in the specifi- 
cations for the analysis of JPX powder.^-^® It in- 
volves dispersing the nitrocellulose in 2/1 ether-al- 
cohol, evaporating part of the ether, and precipitat- 
ing the nitrocellulose with water. The resulting mix- 
ture is then evaporated, and the residue is dried to 
constant weight. 

An alternative procedure involves dispersing the 
nitrocellulose in acetone, and precipitating it by 
pouring the acetone solution into a large volume of 
a dilute aqueous solution of sodium chloride. The 
precipitate is then filtered on a sintered-glass funnel, 
washed with water, and dried to constant weight. 

The Xaval Powder Factory procedure has given 
quite satisfactory results for the analysis of most 
smokeless powders, but the molecular weights of 
nitrocelluloses are markedly decreased by this treat- 
ment. The procedure involving solution in acetone, 
precipitation, and filtration is to be preferred for the 
analysis of powders containing a considerable amount 
of water-soluble inorganic salt which must be sep- 
arated before the nitrocellulose can be determined 
accurately. A method utilizing this procedure was 
developed for the analysis of EJA powders.®® 

Estimation of Nitrogen in NitroceUutose. The du 
Pont nitrometer is customarily used for the estima- 
tion of nitrogen in nitrocellulose,^®® it has proved to 
be entirely satisfactory for the analysis of dried one- 
gram samples of commercial nitrocellulose; however, 
low results have sometimes been obtained with sam- 
ples that had been subjected to the Xaval Powder 
Factory procedure described above. Those nitrocel- 
luloses which gave low results contained 12.6^ or 
less of nitrogen and were almost completely soluble 
in 2/1 ether-alcohol; they formed gelatinous precipi- 
tates when water was added and dried to ‘‘liorn}^’ 
lumps. If an attempt was made to dissolve these 
samples in sulfuric acid before the resulting solutions 


were shaken in the nitrometer, the results were im- 
proved but were not always satisfactory. Therefore 
the nitrometer, although it is the most accurate pro- 
c-edure for the estimation of nitrogen in commercial 
nitrocellulose, cannot be recommended for the analy- 
sis of samples that have been colloided with solvent 
and then precipitated. 

A Devarda procedure has also been employed for 
the estimation of nitrogen in 0.1-g samples of nitro- 
cellulose.^-® This proc-edure involves hydrolysis of the 
nitroc-ellulose in a solution of sodium hydroxide and 
hydrogen peroxide, reduction of the nitrate ion with 
Devarda’s alloy, and distillation and titration of the 
resulting ammonia. This procedure has given very sat- 
isfactory results for the analysis of samples of com- 
mercial nitrocellulose. Like the nitrometer, the De- 
varda procedure gave low results for the analysis of 
some samples of precipitated nitrocellulose, but a 
modification of this procedure^®® in which sodium per- 
oxide is substituted for hydrogen peroxide was found 
to give results accurate within about one-half per cent 
of the nitrogen present. The modified Devarda proce- 
dure is recommended for the estimation of nitrogen 
in samples of commercial nitrocellulose, when less 
than one gram is available and in samples of precipi- 
tated nitroc-ellulose. 

Several attempts were made to estimate nitrogen 
in nitrocellulose by reduction with ferrous chloride 
and estimation of the resulting ferric ion by a pro- 
cedure similar to that used for the determination of 
nitroglycerin discussed below. The results were unsat- 
isfactory. 

Procedures for the Identification and 
Quantitative Estimation of Xiteic 
Esters and Xitro Compounds 

Identification by X-ray Diffraction. X-ray diffrac- 
tion powder photographs are of considerable assistance 
in identifying unknown crystalline constitutents en- 
countered in explosives. In order to aid in this identi- 
fication, X-ray photographs have been taken of several 
crystalline explosive constituents of propellants, and 
tables of interplanar spacings and diagrams illustrat- 
ing the relative positions and intensities of the ob- 
served reflections have been collected.^®^ Among the 
substances for which data are presented are the fol- 
lowing explosives: PETX, 4,6-dinitrotoluene, TXT, 
picric acid, ammonium picrate, guanidine picrate, 
Haleite, nitroguanidine, Fivonite, DIXA, RDX, yS- 
HMX, and QDX (SEX). 

Analysis by Chemical Procedures. The most satis- 


124 


PROPELLANTS 


factory procedure for the estimation in a powder of 
nitric esters, other than nitrocellulose, involves the 
titration of ferric ion with a solution of titanoiis 
chloride. A sample of the powder is extracted and the 
solvent is evaporated from the extract, the residue 
from the evaporation is dissolved in glacial acetic acid, 
and an aliquot portion of this solution is then reduced 
by a mixture of ferrous chloride and hydrochloric 
acid, and the resulting ferric ion is titrated with a 
standard solution of titanous chloride with the use 
of ammonium thiocyanate as indicator.^^®^’^'"^-’^^® 

This procedure has been found to be entirely satis- 
factory for the determination of nitroglycerin and of 
diethylene glycol dinitrate in smokeless powder. 

It has been found that the detectable nitroglycerin 
in extracts of JPN-type powder decreased with time 
if the solutions to be analyzed are allowed to stand 
either in ether or in glacial acetic acid. Storage of 
extracts for longer than one day is not advisable; but 
if storage is necessary, the rate of the apparent de- 
terioration of the extract can be decreased by low 
temperature. 

Xo attempts were made to analyze powders contain- 
ing pentaerythritol tetranitrate, but analyses of a 
purified sample of this explosive by the procedure 
described above were low by approximately one per 
cent.^^® 

Fivonite (2,2,5,5-tetramethylolcyclopentanone tet- 
ranitrate) and DINA (diethanolnitramine dinitrate) 
could not be titrated quantitatively by the standard 
procedure, but satisfactory results were obtained if 
2.0 N ferrous chloride was substituted for the usual 
0.7 N solution. Only the nitric ester groups in DINA 
are reduced under these conditions; the nitramino 
group is apparently unaffected. Satisfactory results 
were obtained for the analysis of powders of modified 
C'ordite N composition which contained these explo- 
sives. 

Nitroguanidine was slowly reduced under the con- 
ditions described above, but the results of a few pre- 
liminary experiments were not quantitative.^^® Since 
nitroguanidine is somewhat soluble in ether, it may 
interfere with the estimation of nitric esters by the 
usual procedure. Therefore, powders containing this 
substance should be extracted with carl)on tetrachlo- 
ride instead of with ether. The only nonchromato- 
graphic procedure studied at the California Institute 
of Technology for the determination of nitroguani- 
dine in smokeless powder was a gravimetric British 
procedure based on the loss in weight resulting from 
extraction with hot water.^®^ 


Dinitrotoluene supposedly is not reduced by ferrous 
chloride in the presence of nitroglycerin, but it can 
be determined by reduction with an excess of titanous 
chloride and back titration with a standard solution 
of ferric alum. This procedure has been found to be 
quite satisfactory for the determination of dinitro- 
toluene in FNH powder. 

The titanous chloride solution used in the titra- 
tions described above is customarily standardized 
against ferric ion obtained by oxidizing a known quan- 
tity of Mohr’s salt. The procedure described in the 
government specifications involves oxidizing the 
sample of Mohr’s salt by titrating it with perman- 
ganate to the usual end point. A more rapid and 
equally satisfactory procedure is to oxidize the sample 
with bromine and to boil off the excess bromine before 
titration with titanous chloride. 

PnOCEDURES FOR THE QUANTITATIVE ESTIMATION 

OF Stabilizers and Nonexplosive Plasticizers 

The results of studies on nonchromatographic pro- 
cedures for the determination of stabilizers and non- 
explosive plasticizers incorporated in American and 
foreign propellants are presented below. Because of 
the differences in the chemical properties of these con- 
stituents, the material has been organized according 
to substances instead of according to procedures as 
in the preceding section. 

Determination of Centralite. The customary chem- 
ical procedures for the determination of centralite in 
smokeless powder involve bromination to dibromo- 
centralite. Gravimetric procedures^^”'^^^ which are now 
in use are more time-consuming than volumetric pro- 
cedures, and therefore have not been used extensively 
in this country. The two volumetric bromination pro- 
cedures which are in common use are the carbon tet- 
rachloride procedure of the Hercules Powder Com- 
pany and the alcohol procedure of the Naval Pow- 
der Factory and the Picatinny Arsenal.^^®*^ In each 
procedure the sample to be analyzed is dissolved in 
the specified solvent and is treated with a known ex- 
cess of a standard solution of bromate-bromide. An 
excess of hydrochloric acid is added, and the centralite 
is brominated by the bromine which is liberated. An 
excess of potassium iodide is then added, and the 
iodine which is produced is titrated with a standard 
solution of thiosulfate. The carbon tetrachloride pro- 
cedure gives very satisfactory results, but the manipu- 
lations are somewhat cumbersome because the two- 
phase system must be shaken vigorously during the 
bromination and also during titration. The technique 


pTNi- 1 i :>i :.nTTa~D 


THE ANALYSIS OF POWDERS 


125 


of the alcohol procedure is easier because the hroTiiina- 
tion aud titration are carried out in a one-phase sys- 
tem, but the time and temperature of bromination 
must be controlled carefully in order to avoid errors 
due to bromination of the solvent. The advantages of 
both procedures can be combined in a one-phase sys- 
tem which is inert to bromine if glacial acetic acid is 
used for the organic solvent. The details of the acetic 
acid procedure and the results of the analyses of repre- 
sentative powders by it are })resented in a formal 
report. 

Powder samples which are to be analyzed for cen- 
tralite by volumetric bromination procedures should 
not be extracted with diethyl ether, because peroxides 
in the ether may interfere with the subsequent analysis 
of the extract. 

Extracts of JPN powders can be stored at room 
temperature for at least two weeks in methylene 
chloride, or in glacial acetic acid without apparent 
decrease in the amount of centralite detected by volu- 
metric bromination. 

X-ray dilfraction data for the identification of 
ethyl centralite have been obtained. 

Determination of Diphenylamine. Three quite dif- 
ferent procedures are in general use for the esti- 
mation of diphenylamine in smokeless powder: the 
nitric acid-digestion procedure for the estimation of 
^^totaP^ diphenylamine, the soda-distillation proce- 
dure for the estimation of ‘^available^^ diphenylamine, 
and the chromatographic-spectrophotometric proce- 
dure for the estimation of ^bictuaP’ diphenylamine. 
Critical studies 'have been made of each of these 
procedures.’"*® 

The nitric acid-digestion procedure’*® involves the 
digestion of a powder sample with a mixture of nitric 
and acetic acids under conditions which lead to al- 
most complete nitration of the stabilizer to hexani- 
trodiphenylamine, which is estimated gravimetrically. 
Since not only the unreacted diphenylamine but also 
all of the partially nitrated derivatives are estimated 
by this procedure the result is reported as total di- 
phenylamine. This procedure is satisfactory for the 
purposes for which it is intended. 

The soda-distillation procedure for the estimation 
of available diphenylamine involves the decomposition 
of the powder with aqueous sodium hydroxide and the 
distillation of the resulting mixture with steam. The 
distillate is then extracted, and the extract is analyzed 
for diphenylamine by gravimetric or volumetric 
bromination procedures. It is claimed that any N- 
nitrosodiphenyl amine is converted to diphenylamine 


under the conditions of the soda distillation and is 
ultimately estimated as such. Since N-nitrosodiphen- 
ylamine is also thought to exert a stabilizing action 
on the powder, the soda-distillation procedure may be 
said to measure the total percentage of diphenylamine 
and derivatives available for stabilization. 

Subsequent studies have indicated that the soda- 
distillation and gravimetric bromination procedures 
determine the approximate total amount of diphcn- 
ylaniine and N-nitrosodiphenylamine in a powder 
sample, but that the results tend to be somewhat low. 
The volumetric bromination procedure is not satis- 
factory for the analysis of distillates from powders 
containing a considerable amount of X-nitrosodiphen- 
ylamine, but British workers’^® claim that results 
agreeing with those from gravimetric bromination can 
be obtained if the distillate is reduced with titanous 
sulfate before it is extracted and analyzed. 

The chromatographic procedures described below 
for the estimation of actual diphenylamine and of 
diphenylamine derivatives are recommended if it is 
desired to estimate the percentages of unreacted di- 
phenylamine and of partially nitrated products in a 
sample of smokeless powder. 

Ether peroxides interfere with the volumetric de- 
termination of diphenylamine just as they do with 
that of centralite. 

X-ray dilfraction data for the identification of di- 
phenylamine and of some of its partially nitrated de- 
riMitives have been obtained. 

Determination of Diethyl Phthalate and Dihutyl 
PhthaJate. The digestion procedure involving saponi- 
fication of phthalate esters during digestion of the 
powder with nitric acid, precipitation of lead phthal- 
ate, and estimation of lead in the precipitate as lead 
sulfate’^®®’’^’ is tedious but is claimed to give repro- 
ducible results in the hands of an experienced oper- 
ator. 

In addition to the chromatographic-spectrophoto- 
metric procedure described in Section 6.11.2, a pro- 
cedure involving chromatographic separation and 
gravimetric estimation has been developed at the Rad- 
ford Ordnance Works.’®^ Attempts at the California 
Institute of Technology to develop a procedure in- 
volving chromatographic separation and volumetric 
estimation were promising but were not carried to 
completion.’®® 

Determination of Urethanes. Some attempts were 
made to develop chemical procedures for the estima- 
tion of ethylphenylurethane and diphenylurethane. 
These substances did not absorb bromine directly but 


126 


PROPELLANTS 


could be hydrolyzed with alkali under drastic condi- 
tions to ethylaniline and diphenylamine, respectively ; 
these hydrolysis products could then be estimated by 
bromination. Work on the application of these proce- 
dures to the analysis of smokeless powders was dis- 
continued because the chromatographic-spectrophoto- 
metric procedures described below were found to be 
thoroughly satisfactory. 

Determination of Acardite. Acardite can be esti- 
mated quantitatively by the volumetric ])romination 
procedure involving acetic acid. A chromatographic 
procedure for the estimation of this substance is de- 
scribed below. 

Determination of Dipheniflformamide. Diphenyl- 
formamide does not react with l)romine at a significant 
rate under customary conditions of analysis. The re- 
sults of experiments involving alkaline hydrolysis and 
estimation of the resulting diphenylamine were en- 
couraging, but detailed analytical procedures were not 
developed because of the satisfactory nature of the 
chromatographic procedure described below. 

PuOCEDUUES FOR THE QUANTITATIVE ESTIMATION 

OF Volatile and Inorganic Constituents 

Determination of Moisture and Volatile Solvent. 
On the basis of existing specifications, four methods 
for the determination of moisture in solventless double- 
base powder (the desiccation, the cone-and-dish, the 
carbon tetrachloride distillation, and the Karl Fischer 
procedures) were selected and subjected to a critical 
investigation. The results are collected in a formal 
report.^®* 

Desiccation over concentrated sulfuric acid was 
found to be the most reproducible procedure of those 
examined. Although at least four days is required for 
the determination of moisture by this procedure, the 
time of the analyst per analysis is less than that re- 
quired for any of the other procedures. ^Additional ex- 
periments indicated that desiccation under these con- 
ditions removes virtually all of the moisture but not 
more than a few hundredths of a per cent of the other 
constituents present in a powder sample. 

The cone-and-dish procedure^®® for the estimation 
of total volatile matter is rapid and gives reasonably 
satisfactory results for the analysis of solventless pow- 
ders containing from 0.2 to 0.4% moisture; however, 
its success appears to be due to a balance between in- 
complete removal of water and loss of other constitu- 
ents from the system. 

Reflux distillation of the powder sample with car- 
bon tetrachloride, and collection of the water in a cali- 


brated trap is a satisfactory procedure for rapid control 
analyses in which an accuracy of 0.05% is satisfactory. 
Errors due to sampling are reduced because a 100-g 
sample of powder is required for this procedure. 

Procedures involving the use of Karl Fischer re- 
agent^°® are satisfactory when proper precautions are 
taken, but they cannot be recommended for control 
analyses. 

No studies were made of any procedure except the 
cone-and-dish for the determination of volatile con- 
stituents other than moisture. 

Determination of Nonvolatile Inorganic Constitu- 
ents. New chemical, spectrographic, and polarographic 
procedures that have been developed for the identifica- 
tion and estimation of nonvolatile inorganic constitu- 
ents in smokeless powder are described in a formal 
report the findings are summarized in the fol- 

lowing paragraphs. 

Routine chemical procedures may be employed for 
the semi-quantitative analysis of cationic and anionic 
constituents in smokeless powders. Most of these pro- 
cedures are rather tedious and are not highly precise 
when applied to the estimation of constituents which 
are present only as traces. However, procedures for the 
estimation of moderate amounts of such constituents 
as graphite, carbon black, potassium nitrate, potassium 
sulfate, potassium perchlorate, and titanium dioxide 
have been shown to be satisfactory and are described 
in reference 157; procedures for the estimation of 
carbon black and potassium perchlorate in EJA pow- 
ders are described in more detail in a formal report on 
a complete procedure for the analysis of these powders. 

A rapid spectrographic procedure which has been 
developed for the semi-qnantitative estimation of 
cationic constituents is a great improvement over the 
more cumbersome chemical procedures. The spectro- 
graph has proved to be very valuable for the prelimi- 
nary study of a powder of unknown composition and 
for the estimation of metals present only as traces. 

Polarographic procedures have also proved to be 
helpful for the determination of chloride, nitrate, 
nitrite, titanium, barium, and alkali metals. 

A simple conductometric method has been devel- 
oped for the rapid approximate determination of the 
total percentage of water-soluble inorganic salts in a 
powder. 

In addition to the various semi-quantitative pro- 
cedures described above. X-ray diffraction studies have 
been found to be a valuable aid in the identification of 
crystalline constituents. These studies are especially 
helpful in the examination of mixtures because they 


((■()\-rii)TA-TTTT?l 


THE ANALYSIS OF POWDERS 


127 


provide information concerning the combination of 
cations and anions in the original powder. Diffraction 
data have been obtained for magnesium, aluminum, 
ammonium nitrate, potassium nitrate, strontium ni- 
trate, barium nitrate, potassium sulfate, barium sul- 
fate, sodium chlorate, potassium chlorate, potassium 
perchlorate, and titanium dioxide (rutile). 

Chroiiiatographic-Spectrophotometric 

Methods"^ 

In 1906 a new method for the separation of the 
constituents of a mixture by selective adsorption was 
developed by the Russian botanist Tswett. This meth- 
od, which was based on the unidirectional flow of a 
solution of the mixture through a column of adsorbent, 
was especially adaptable to the separation of colored 
substances ; it was therefore termed ‘^chromatographic 
analysis” or, more simply, “chromatography.” Al- 
though the potentialities of this new technique were 
recognized by a few investigators, little application of 
it was made prior to 1931. Since that year, however, 
the use of chromatography has become widespread, 
especially in the separation and purification of natui- 
ally occurring organic compounds; its application to 
inorganic substances has been limited. 

When work on propellants was begun at the Cali- 
fornia Institute of Technology in the spring of 1942, 
the applicability of chromatography to the problems 
of powder chemistry was recognized at once, and a 
series of investigations was undertaken under OSRD 
Contract OEMsr-702. After July 1, 1943, this work 
was continued and extended under OSRD Contract 
OEMsr-881. 

The chromatographic method has proved to be espe- 
cially valuable in the study of explosives when it is 
combined with the technique of absorption spectropho- 
tometry. By the use of chromatography it is possible 
to effect many separations and purifications which 
would be difficult or impossible to achieve without this 
technique ; the compounds so isolated can, in most 
cases, be simply and accurately identified and esti- 
mated spectrophotometrically. 

The following summary of the chromatographic and 
spectrophotometric investigations which were done,® 
includes a very brief general description of the chro- 
matographic method, a discussion of the development 
of the chromatographic-spectrophotometric method 
and of its application to the study of smokeless pow- 

'This section is taken from a report submitted by Kenneth 
N. Trueblood. 

«OSRD Contracts OEMsr-702 and OEMsr-881. 


ders and related substances, and a short discussion of 
certain phenomena and relations which were observed 
during these studies and which are of general applica- 
bility in chromatographic and spectrophotometric work. 

The general methods of chromatography, the devel- 
opment of chromatographic-spectrophotometric tech- 
niques for application to the study of smokeless pow- 
ders, the chromatographic properties and absorption 
spectra of all of the compounds studied, and proce- 
dures for the quantitative determination of all of the 
important constituents of powders have been described 
in detail in reports issued from the California Insti- 
tute of Technology.'^®'^®^ 

A colored motion picture which illustrated the op- 
erations and techniques of chromatography has also 
been prepared. 

The CHROMATOGrtAPHic Method 

The chromatographic method is best adapted to the 
isolation of compounds in quantities which are of the 
order of a few hundredths of a milligram to about 
fifty milligrams. The chromatographic process is car- 
ried out in a vertical glass tube which consists of two 
sections, a long cylinder and a special adapter by 
means of which the cylinder is mounted on a filter 
flask. The chromatographic column is formed, or 
“packed,” by pouring the adsorbing material, the ad- 
sorbent, into the tube under the full force of an as- 
pirator, by means of which a strong suction is main- 
tained throughout the chromatographic experiment. 
The mixture to l)e analyzed is dissolved in a small 
volume of some selected solvent from which tlie sub- 
stance will be strongly adsorbed. This solution is then 
poured upon the adsorbent and drawn by continuous 
suction into the column. Upon the subsequent addi- 
tion of portions of the same solvent, or of a different 
solvent, or mixture of solvents, the adsorbed substances 
migrate slowly down the column at rates which depend 
upon their respective adsorption affinities. This pro- 
cedure is termed development, and the solvent or mix- 
ture of solvents which is used to effect the separation 
of the adsorbed substances is called the developer. 
When development has been properly carried out the 
various solutes are distributed through the adsorbent 
in a series of well-defineJ zones, separated from each 
other by portions of the column which are free of ad- 
sorbed material. The most strongly adsorbed substance 
is nearest the top of the column, and the least strongly 
adsorbed nearest the bottom. When proper separation 
has been attained the development is halted and the 
column is extruded from the tube. 


128 


PROPELLANTS 


If some of the constituents of the mixture form 
colorless zones on the column, these zones may usually 
he located on the extruded chromatogram by applying 
thin streaks of suitable reagents along the entire length 
of the column ; a suitable reagent for a particular sub- 
stance is one which produces a noticeable color 
throughout a zone of the compound. The location of 
colorless zones for which a streak reagent cannot be 
found is a more difficult and tedious task and can usu- 
ally only be done empirically ; occasionally use can be 
made of some special property of a compound such as 
fluorescence in ultraviolet light. 

After the zones have been located they are separated 
from each other by cutting the column into sections; 
all portions which are contaminated with streak re- 
agent are carefully removed and discarded. The in- 
dividual zones are then transferred to separate flasks 
and mixed with a suitable solvent Avhich removes the 
adsorbed substance from the adsorbent ; this process is 
termed ehdion and the solvent which is used is called 
the eluent. The suspended adsorbent is removed from 
the mixture by filtration through a sintered glass fun- 
nel, and elution is completed by drawing additional 
quantities of eluent through the filter cake. The filtrate 
thus obtained is termed the eluate. The process of elu- 
tion is the final step in the chromatographic procedure. 

The eluate of each of the separate zones contains, 
ideally, only one compound ; sometimes, however, it is 
impossible to achieve a complete separation of all of 
the constituents of a mixture in one chromatogram. 
In such case certain of the zones will contain two or 
mo]*e compounds. Such mixtures can usually be sepa- 
rated by rechroniatography ; the eluate of the zone is 
freed of solvent by evaporation, and the residue is dis- 
solved in a suitable solvent, and is again chromato- 
graphed, usually under slightly different conditions 
than before. 

After each zone has been purified to the desired 
extent, the course of further investigation of the eluate 
will depend upon the nature of the substance or sub- 
stances in the eluate and upon the objectives of the 
work. A discussion of some of the possible procedures 
is given here. 

Devklopmknt of the Cheomatographic-Specteo- 

PHOTOMETEIC METHOD FOE APPLICATION TO THE 

Study of Smokeless Towdees and Related Sub- 
stances 

A considerable amount of preliminary experimen- 
tation was necessary before the methods of chromatog- 
raphy and spectrophotometry could he applied suc- 


cessfully to the analysis and study of smokeless pow- 
ders and related substances. A brief account of the 
principal problems which arose and of the manner in 
which these problems were solved is presented in the 
following paragraphs; a detailed discussion is given 
in references 160 to 162. 

The first and perhaps the most important task was 
the selection of a suitable chromatographic adsorbent. 
Some early success was achieved with calcium hydrox- 
ide, Neutral Filtrol, alumina, and talc; however, each 
of these adsorbents possessed certain undesirable char- 
acteristics. Silicic acid, on the other hand, appeared 
to be entirely satisfactory for the chromatography of 
the constituents of smokeless powder and was, there- 
fore, used almost exclusively throughout the entire 
program of work; the discussion tvhich follows ap- 
plies to chromatographic icorh on silicic acid unless 
specifically stated otherwise. Because the rate of filtra- 
tion of solvents through silicic acid is extremely slow 
it is desirable for chromatographic purposes to mix the 
silicic acid with a filter aid. A mixture of two parts 
by weight of Merck’s reagent silicic acid with one part 
of Celite 535, a product of the Johns-Manville Corpo- 
ration, is generally satisfactory as an adsorbent ; minor 
variations from the 2/1 ratio are sometimes desirable 
because of variations in the rates of filtration through 
different lots of silicic acid. 

Preliminary experiments on the chromatography 
of nitrocellulose met with no success; furthermore the 
presence of this material on the column during the 
chromatographic determination of the other constitu- 
ents of powder proved to be very objectionable. Hence 
a procedure for the quantitative separation of the 
nitrocellulose from the other organic constituents 
which are present in a smokeless powder was necessary. 
Extraction of the powder in a Soxhlet apparatus has 
been used for this purpose by powder chemists, but an 
excessively long time is usually required for complete 
extraction. It was found, however, that the efficiency 
of the method can be greatly increased by first sub- 
dividing the powder into pieces about 0.1 mm thick; 
this can be done conveniently with a sliding micro- 
tome, using a special cutting tool for especially hard 
jwwders. A double-base powder can then be completely 
extracted with anhydrous ether or methylene chloride 
in two or three hours; a somewhat longer time is re- 
(piired for FNH or single-base Pyro powders. With the 
exception of inorganic material, nitrocellulose, and a 
few other substances which are extremely insoluble in 
the extracting agents, all the common constituents 
of powders will be present in the extract. 


U'ONFlhEXTIATX 


THE ANALYSIS OF POWDERS 


129 


llecause ether is an eluent for most substances, it 
must he removed entirely from an extract before 
chromatography, in order tliat the substances in the 
extract will be adsorbed and not merely washed 
through the column. The complete removal of the 
ether is satisfactorily accomplished by evaporation in 
a slow stream of air. The residue may then be dissolved 
in benzene, diluted with about an equal volume of lig- 
roin, and chromatographed. A methylene chloride ex- 
tract need not be evaporated ; it may be chromato- 
graphed directly after dilution with about an equal 
volume of ligroin. Methylene chloride is at least as 
efficient as ether as an extracting agent for powder; 
indeed, some evidence indicates that it may even be 
superior. 

In general a satisfactory solvent for placing a com- 
pound on a chromatographic column, is one which is 
a very weak developer for the compound ; if the solvent 
is a strong developer or an eluent for the particular 
substance, tlie latter will be spread throughout most 
or all of the column and proper development will be 
impossible. Ligroin is essentially an ideal solvent for 
placing most substances on the chromatographic col- 
umn because it has almost no developing action. If a 
compound is insoluble in ligroin it is generally possible 
to obtain a satisfactory solvent by dissolving the com- 
pound in a stronger developer and diluting the result- 
ing solution with ligroin until the developing action is 
sufficiently weakened. Benzene is most frequently used 
with ligroin in this manner. 

It must be emphasized that the term ^hleveloper’^ is 
a relative one; a mixture of solvents which is a good 
developer for one compound may ])e an eluent of a 
second substance or may leave a zone of some third 
substance at the top of the column. In general the 
nore polar a solvent, the stronger its developing action. 
Thus, ligroin is the weakest developer, benzene and 
methylene chloride are somewhat stronger, and ether, 
ethyl acetate, acetone, and ethanol are powerful de- 
velopers or eluents for most substances. By judicious 
selection and admixture of these solvents, and of others 
in certain special cases, a wide range of developing 
actions may readily be achieved. 

The most common and convenient eluents are ether, 
ethanol, and a mixture of equal volumes of acetone and 
ether. A solvent which is used as an eluting agent 
should have no properties which interfere with or 
complicate subsequent operations upon the eluate. 

Most of the common constituents of smokeless pow- 
ders are colorless ; the chief exceptions are the nitra- 
tion products of the stabilizers, and these compounds 


are noinially present only in small amounts. The po- 
sitions of the colored zones on a column may sometimes 
serve as convenient indicators of the approximate posi- 
tions of the colorless zones. However, accurate loca- 
tion of most colorless zones can be conveniently accom- 
plished only by means of a streak reaction with some 
appropriate reagent. It is desirable that the streak re- 
agents which are employed react with a wide variety of 
compounds, so that the number of streaks necessary to 
locate all of the colorless zones on a particular column 
may be kept to a minimum. Many streak reagents 
were developed for the various types of compounds 
which are to be found in smokeless powders ; the most 
useful of these are a solution of ceric sulfate or vana- 
dium pentoxide in sulfuric acid, applicable to a wide 
variety of phenyl-substituted ureas, urethanes, and re- 
lated compounds; a solution of diphenylamine in sul- 
furic acid, applicable chiefly to nitric esters and N- 
nitroso compounds; an aqueous solution of sodium 
hydroxide or potassium hydroxide, a satisfactory re- 
agent for many nitro compounds; and a solution of 
sodium nitrite in sulfuric acid, which gives colors 
with diphenylamine and certain of its derivatives. 
Several other streak reagents were found to be ap- 
plicable to a limited number of compounds. 

An ultraviolet spectrophotometer affords the sim- 
plest and most generally applicable means for the pre- 
liminary identification of unknown substances and the 
quantitative estimation of known compounds. With 
the aid of this instrument it is possible to identify as 
little as a few hundredths of a milligram of many 
compounds and to measure accurately quantities of the 
order of one milligram. Hence an ultraviolet spectro- 
photometer is almost indispensable for use in conjunc- 
tion with the technique of chromatography. 

In preliminary experiments on the quantitative re- 
covery of certain constituents of smokeless powders 
from the chromatographic column, it was discovered 
that impurities in the adsorbent and in the various 
organic solvents used in the procedures made it im- 
possible to obtain reproducible results. It was found 
that the solvents could be rendered sufficiently pure 
by distillation in an all-glass still; this method of puri- 
fication was used thereafter for all solvents. The re- 
moval of the impurities in the adsorbent could be 
accomplished satisfactorily by washing the column 
with a specified volume of anhydrous ether and then 
with ligroin before introducing the sample. This ‘^pre- 
washing” treatment tends to make the adsorbent 
somewhat stronger by removing water from it; it was 
found later that a modified prewash employing a 


f?)VFTnF.UTTAT;i 


130 


PROPELLANTS 


mixture of equal volumes of acetone and ether in- 
creases the strength of the adsorbent even more by 
removing additional water. The prewashing treat- 
ment first described was used in most of the chromato- 
graphic work and was generally satisfactory ; the mod- 
ified procedure was employed only in special cases 
when the ordinary procedure was inadequate. 

The most suitable solvent for spectrophotometric 
measurements is absolute ethanol. Many of the solvents 
which are commonly used as developers show appre- 
ciable absorption in the ultraviolet region of the 
spectrum, and, hence, interfere with a spectrophoto- 
metric measurement. Since an extruded column is 
usually still wet with an appreciable quantity of the 
developer some of this solvent will be carried, with 
the adsorbed substance, into the eluate and will there- 
by render impossible spectrophotometric measure- 
ments on the eluate. The objectionable solvent can 
readily be eliminated, however, by evaporation to dry- 
ness under reduced pressure. The absorption spectrum 
of the residue can then he measured after the material 
lias been dissolved in absolute ethanol. 

If the adsorbed compound is appreciably volatile it 
will be partially or completely lost when the eluate is 
evaporated to dryness. Hence, with such a compound 
an alternative method of removing the developer is to 
be preferred : after development has been completed, 
the chromatogram is washed with 28 to 38 C ligroin in 
order to remove the less volatile solvents, the zone is 
cut in the usual fashion, allowed to dry in air for about 
one hour, and then eluted directly with ethanol. 

Certain modifications in the procedure outlined 
above are necessary in quantitative work. Calibrated 
glassware must be employed in diluting the extract 
of the powder, and in measuring the sample for 
chromatography, and special care must be taken to 
insure that the sample is transferred quantitatively 
to the column. In a quantitative determination the 
streak reagent is used only to delimit the zone and is 
not applied to the main portion ; thus the losses because 
of contamination by streak reagent are minimized. 

Before a compound can be quantitatively estimated 
with the aid of the spectrophotometer it is necessary 
that an extinction coefficient at a suitable wavelength 
be accurately measured with a pure sample of the 
substance. The most convenient wavelength is gener- 
ally one at wliicli the absorjdion spectrum of the com- 
pound has a maximum. 

In all quantitative spectrophotometric work it is 
essential that calibrated glassware be used and that the 
temperature be controlled, because the optical density 


of a solution of a given compound varies directly with 
concentration. In addition it is necessary to make a 
blank correction for the entire chromatographic pro- 
cedure and certain minor corrections incident to the 
method of measurement of the optical density. 

Quantitative measurements can be made without 
the aid of a spectrophotometer, but they are consid- 
erably less convenient. For example, it is possible to 
isolate PETN by chromatography and to determine 
the quantity by direct weighing or to isolate nitro- 
glycerin by chromatography and to determine the 
quantity by the usual volumetric procedure. In gen- 
eral, however, spectrophotometric estimation is much 
to be preferred when it is feasible; nitric esters are 
among the few constituents of smokeless powders 
which cannot conveniently be estimated spectrophoto- 
metrically. 

Applications of the Chromatogeaphic-Spectro- 
PHOTOMETRIC MeTHOD TO THE StUDY OF SmOKELESS 

Powders and Related Substances 

The chromatographic-spectrophotometric method 
can be applied successfully to a variety of analytical 
problems in powder chemistry ; the applications which 
have already been made range from routine quantita- 
tive estimation of the common constituents of powders 
to exhaustive qualitative and quantitative analyses of 
powders of unknown composition. The exact manner 
in which a particular problem should be attacked can- 
not of course be specified, but the following generali- 
zations can safely be made. 

If the components of the mixture to be analyzed ai'c 
already known, as, for example, in the analysis of an 
American propellant, it is generally necessary only 
to experiment with pure samples of these compounds 
until an effective scheme for the quantitative separa- 
tion and estimation of the desired material has been 
devised. In the analysis of a powder of uncertain com- 
position, such as a foreign propellant or an artificially 
aged powder, a complete qualitative analysis must first 
be made. Even when all the components of a powder 
are not known it is sometimes possible to predict what 
compounds are likely to be present; a preliminary 
study of the properties of these substances will then 
greatly simplify their detection and estimation in the 
powder. Frequently, however, completely unfamiliar 
compounds are detected ; the general manner in which 
the identification of such substances is effected can 
be outlined briefly as follows. 

The chromatographic behavior, streak reactions, and 
absorption spectrum of an unkown compound are first 


THE ANALYSIS OF POWDERS 


13 J 


compared with those ot* all of the known coinponnds 
which have been investigated. This procedure often 
affords important clues as to the nature of the uniden- 
tified material ; for, after a sullicient number of com- 
pounds have been examined, certain correlations can 
often be established between the structure of a com- 
pound and its streak reactions, chromatographic be- 
havior, and absorption spectrum. Sometimes an un- 
known compound may be isolated in sufficient quan- 
tity and purity for melting-point determination, mi- 
croanalysis, or other appropriate treatment. 

If the readily available evidence as to the identity 
of the unknown is insufficient for positive identifica- 
tion, the only remaining course is to prepare or ob- 
tain the compounds Avhich have the most likely struc- 
tures and to compare the properties of these com- 
pounds with those of the unknown material. Hence, 
a complete qualitative analysis is often a long, labori- 
ous task. 

During the course of the studies of smokeless pow- 
ders and other explosives by chromatographic and 
spectrophotometric methods, detailed investigations 
wei’e made of the chromatographic behavior of a wide 
variety of compounds. The characterization of the 
chromatographic behavior of a compound involves 
the determination of a suitable solvent for placing it 
on the column, of a means for locating it on the col- 
umn, of its behavior with several different types of 
developers, of methods by which it may be separated 
from other compounds of similar adsorption affinity, 
and of a satisfactory eluent. More than thirty ex- 
plosives, stabilizers, and plasticizers were investigated, 
including all of the common constituents of single- 
base and double-base powders, with the exception of 
nitrocellulose and inorganic substances. xY detailed 
and complete investigation was made of the chroma- 
tographic behavior of IU)X, and of nine of the com- 
pounds closely related to it in connection with the 
development of a method for the analysis of com- 
mercial samples of ItOX for impurities (see Section 
1.2). Extensive investigations of the transformations 
of diphenylamine and centralite in their roles as 
stabilizers in smokeless powders required a thorough 
study of the chromatographic properties of about 
twenty nitration and nitrosation products of diphen- 
ylamine and about twenty-five compounds which are 
related to ethyl centralite. The derivatives of diphen- 
ylamine were chromatographed on calcium hydroxide 
as well as on silicic acid ; the former adsorbent was, 
however, preferable only for a few specialized sep- 
arations. 


The absorption spectra of all the ahove-mentioned 
compounds, and of about fifty others related to them, 
were measured in absolute ethanol Avith a Beckman 
ultraviolet spectrophotometer. The related compounds 
included some substances Avhich Avere considered as 
possible transformation products of diphenylamine or 
centralite but Avhich Avere never detected in poAvders, 
some compounds Avhich Avere prepared for testing as 
stabilizers and plasticizers in experimental poAvders, 
and a feAv miscellaneous compounds. 

Chromatographic - spectrophotometric procedures 
Avere developed for the quantitative estimation of al- 
most all the stabilizers and plasticizers and a feAV of 
the explosives Avhich Avere encountered in American 
and foreign propellants. Most of these procedures 
AA^ere simpler and more general in applicability than 
the older and more conventional chemical methods; 
for several of the compounds no analytical procedure 
other than the chromatographic-spectrophotometric 
one has yet been developed. Methods Avere also de- 
vised for the roughly quantitative estimation of many 
of the transformation products of diphenylamine and 
centralite in poAvders. 

xYlthough the quantitative and roughly quantita- 
tive procedures could be standardized to some extent, 
frequent checking and occasional modification or re- 
vision Avere essential because of the possible presence 
in a poAvder of previously unencountered compounds 
and because of A^ariations in the adsorptive strength 
of the silicic acid from lot to lot. 

Iioiitine Analyses. One of the commonest, though 
least exciting, applications of chromatographic-spec- 
trophotometric techniques has been in routine quan- 
titative analyses for certain common constituents of 
various standard poAvders. 

Precise and reliable methods have been developed 
Avhich are in most cases equal or superior to older 
methods both in convenience and accuracy. Although 
it is not possible to determine nitric esters spectro- 
photometrically, the chromatographic method is of 
great advantage in the analysis of mixtures of these 
substances Avhich are otherAvise difficult to analyze. 
For example, a mixture of nitroglycerin and dieth- 
ylene glycol dinitrate can be separated quantita- 
tively into its components l)y chromatography, and 
the individual esters can then be separately estimated 
by the standard volumetric procedures. 

Analyses of Foreign Propellants. The chromato- 
graphic-spectrophotometric method is best adapted 
for use Avith micro or semi-micro quantities of mate- 
rial, and for this reason it is ideally suited to the 


i()\Fll)l-:N"riA.Q 


132 


PROPELLANTS 


analysis of small samples of smokeless powder of mi- 
kiiown composition. A typical qualitative anal3'Sis re- 
quires perhaps 0.5 g of powder and a quantitative 
analysis can usually he completed with less than 2 g. 
The identification of a hitherto unencountered com- 
ponent of a powder is greatly simplified by a study of 
its absorption spectrum and chromatographic be- 
havior, particularly in regard to its streak reactions. 
If necessary, a few centrigrams of the material can 
readily be isolated for microanalysis. 

Examples of the application of the chromatographic- 
spectrophotonietric method to the analysis of foreign 
})ropellants are included in several reports'®^’^®’’ and 
are discussed in Section G.ll. 

I nresfigations of the Chemical Changes 117/ic/i Ihike 
l^lace in Smokeless Powders under Various Condi- 
tions. The chroniatographic-spectrophotemetric meth- 
od is the only satisfactory technique yet developed for 
studying the complex chemical reactions which take 
place in smokeless powder under various conditions, 
such as aging, irradiation, and storage at elevated tem- 
peratures. The method has so far been applied ex- 
clusively to the study of the transformations of the 
stabilizers, in particular, diphenylamine and cen- 
tralite; the investigation of the degradation products 
of the explosive constituents of a powder would be an 
extremely complex task, especially since the spectro- 
photometer would be of little use. 

An early attempt to study the effects of irradiation 
on several doulfie-hase propellants by spectrophoto- 
metric examination of thin sections of these powders 
met with little success. Although a fairly satis- 
factory method for measuring the absorption coeffi- 
cients of the powders was devised, lack of information 
as to the nature of the absorbing compounds prevented 
a complete appraisal of the effects of the irradiation. 

One of the early applications of chromatographic- 
spectrophotometric techniques Avas in a study of the 
effect on the diphenylamine content of ballistite of 
the processing operations Avhich are incident to the 
i)reparation of this poAvder for use in rocket motors.^®*’ 
It Avas found that the percentage of stabilizer in the 
poAvder decreased negligibly during these operations. 

A variety of techniques Avas used to investigate the 
stability of propellants, as discussed in Section 6.12; 
one of these methods Avas the study of the rate of de- 
])letion of the stabilizer during storage at elevated 
temperatures. It Avas hoped that a comparison of the 
rates of depletion of a given stabilizer in poAvders of 
similar but slightly different composition, Avould in- 
dicate the effects of certain variations in composition 


oJi the relative stabilities of the powders. Among the 
})oAvders Avhich Avere studied after storage at tempera- 
tures near 70 C (about 160 F) AAere trench mortar 
sheet,^'^" a series of modified ballistites,^'’®’^'’^ several 
double-base poAvders Avhich contained TiDX but no 
nitroglycerin,^® and tAvo Albanite poAwlers (see Sec- 
tion 6.7). In addition, a study AA^as made of the rate 
of depletion of diphenylamine in ballistite JP 201 
and in an FNH poAvder, PPL 111, at 80, 90, 100, 
and 110 C in the vacuum stability test.^^® The results 
of all of these studies are discussed briefly in Section 
6 . 12 . 

An exhaustive study Avas made of the transforma- 
tion products of diphenylamine in double-base pow- 
ders,^’^’ and in FNII and single-base pyro powders,’"® 
duilng storage at elevated temperatures. With the 
exception of a compound Avliich contained the cation 
of diphenylamine blue, a triphenylmethane-type pig- 
ment Avhich Avas detected in small amount, all the 
identified products from both types of poAvders Avere 
nitro and N-nitroso derivatives of diphenylamine. 
The derivatiA’es A\liich AA’ere found in double-base 
poAvder may be listed as folloAvs : 

N-Nitrosodiphenylamine N-Nitroso-2,4'-dinitrodi- 
2-Nitrodiphenylamine phenylamine 

4-Nitrodiphenylamine N-Nitroso-4,4'-dinitrodi- 
N-nitroso-2-nitrodiphenyla- phenylamine 

mine 2,2',4-Trinitrodiphenylamine 

N-nitroso-4-nitrodi- 2,4,4'-Trinitrodiphenylamine 

phenylamine 2,2', 4,4'-Tetranitrodiphenylaminc 

2,2'-Dinitrodiphenylamine 2,2',4,4',G-Pentanitrodii)henyla- 
2,4-Dinitrodiphenylamine mine 

2,4'-Dinitrodiphenylamine 2,2',4,4',6,6'-Hexanitro- 
4,4'-Dinitrodiphenylamine diphenylamine 

2,4,6-Trinitrophenol (picric acid) 

According to the results of quantitatiA^e determina- 
tions of diphenylamine and its derivatives in a series 
of samples of ballistite JP 201 AAliich had been stored 
at 71 C, the first reaction of diphenylamine is ap- 
parently an overAvhelming conversion to X-nitroso- 
diphenylamine. After the diphenylamine has been 
exhausted, N-nitrosodipheiiylamiiie decreases rapid- 
ly, and N-iiitroso-l-nitrodiphenylamine and the dini- 
tro and trinitro derivatiA’es make their appearance. 
Tetranitrodiphenylamine appears A\lien the trinitro 
compounds are present in considerable quantity and 
increases rapidly Avhen most of the material is in the 
form of the trinitro derivatives. When the tetranitro 
derivative is present in large quantity, pentanitrodi- 
])henylamine, hexanitrodiphenylamine, and some pic- 
ilc acid arc produced. 

In FNII and a single-base pyro poAvder, the trans- 
formation of diphenylamine had only reached the 


THE ANALYSIS OF POWDERS 


13H 


^tago of tlio ti’iiiiti’o derivatives in the last samples 
Avhieli were studied; however, u}) to this point the 
course of the transformation resembled closely that 
which was found to take place in donble-base powder. 

Tlie actual reactions involved in the consecutive 
transformations of diphenylamine into its derivatives 
are not yet known. There is definite indication that, 
in addition to a scheme of nitrosamine rearrangement 
as in the Fiselier-Hepp reaction, followed by oxida- 
tion, many other types of reactions are responsible for 
the transformations. These possible reactions include 
X - nitrosation, denitrosation, direct nitration of 
amines or nitrosamines, and the oxidation of nitros- 
amines to nitramines followed by rearrangement. 
Studies of several experimental donble-base powders 
in which diphenylamine derivatives were incorporated 
showed that X-nitrosation and denitrosation are im- 
portant in certain stages of the degradation of the 
stabilizer. 

By assuming that the reactions responsible for the 
consecutive transformations of diphenylamine occur 
by a simple scheme and that the reactions are pseudo 
first order, reaction rate constants for the formation 
and destruction of each derivative in donble-base pow- 
der have been determined. Xo corresponding analysis 
lias been performed for the reactions in single-base 
powder. 

An outstanding difference between ballistite and 
single-base and FXH powders lies in the overall rate 
of transformation of diphenylamine and its deriva- 
tives. The rate of transformation in single-base pyro 
powder is only one-tenth that in ballistite; in FXH 
powder, transformation proceeds at an even slightly 
slower rate. In double-base powders which contain 
I\DX in place of nitroglycerin, the rate of depletion 
of diphenylamine is comparable to that in single-base 
powder and is much smaller than that in ballistite. 

After the exhaustion of diphenylamine the percent- 
age of diphenylamine which is accounted for as its 
derivatives falls to a nearly constant level, 60 to Go 
per cent, in single-base as well as in double-base 
powder. In FXH powder, on the other hand, the 
recovery of diphenylamine is substantially 100 per 
cent until the diphenylamine is exhausted and is com- 
paratively high thereafter. It is not known why the 
addition of dinitrotoluene to pyro powder or its sub- 
stitution for nitroglycerin in ballistite should inhibit 
the reactions which are responsible for the loss of 
diphenylamine. 

A careful study of the transformation products of 
ethyl centralite in double-base powders during stor- 


age at about 70 C was likewise niade.“'*^ Both cordite 
JP 76, v.Iiich contains 9% of centralite, and Badford 
Pilot Lot Xo. 142, which contains 1% of this sta- 
bilizer, were investigated. These studies proved to be 
considerably more complex than the investigations 
of the transformation of diphenylamine; the trans- 
formation of centralite takes place more slowly, and 
the course of the reactions is less clear than with 
diphenylamine. 

The identified transformation products of centralite 
may be classified in two general groups. One group 
contains the compounds in which the urea structure 
is still present, and the other those in Avhich it has 
been split. The chief compounds so far detected in 
the first category are 4-nitrocentralite, 4,4'-dinitro- 
centralite, and 2,4,4'-trinitrocentralite ; the latter 
compound has been found only in small amounts in 
tbe longest-heated samples. 2-Xitrocentralite and X- 
ethylcarbanilide are also found but are present in 
much smaller amount than the other compounds. In 
the second category the chief products are X-nitroso- 
X-ethylaniline and X-nitroso-4-nitro-X-ethylaniline ; 
traces of other compounds such as 4-nitro-X-ethylan- 
iline, 2-nitro-X-ethylaniline, 4-nitroaniline, and 4- 
nitrophenol can also be detected. In addition to the 
compounds which have been identified, there are 
several apparently minor unidentified substances 
whose streak reactions and adsorption spectra re- 
semble those of some of the knoAvn derivatives. To 
aid in the study of the course of the transformations 
of the derivatives of centralite, several experimental 
])OAvders AA'liich contained various transformation prod- 
ucts of centralite as stabilizers Avere prepared. 

At 65 the transformation of centralite in cordite 
JP 76 differs notably from that in PPL 142. In 
cordite X-nitroso-X-ethylaniline is the major pri- 
mary transformation product of centralite, although 
some 4-nitrocentralite is also formed; in PPL 142, 
on the other hand, the situation is reversed and 4- 
nitrocentralite predominates. Furthermore the rate 
at Avhich centralite disappears from cordite is about 
five times as great as that at Avhich it is depleted from 
PPL 142. In each poAvder, after depletion of the 
centralite, only about one-half of the centralite Avhich 
has disappeared can be accounted for in terms of 
knoAvn derivatives. It has been determined that no 
more than a minor portion of the ^hnissing’^ centralite 
is volatilized during the heating of the poAvders. 

It is apparent that a considerable amount of Avork 
on the transformations of centralite in double-base 
poAvder remains to be done. In this connection it 


F'r>Ni‘TmcvViAr] 


134 


PROPELLANTS 


should bo meiitioiied that a parallel investigation of 
the applications of chromatography to the examina- 
tion of explosives and, in particular, of heated cordite 
is in progress in Englandd^^'^^® 

Analijsis of Commercial IWX. Chromatographic- 
spectrophotometric techniques were successfully ap- 
plied to the analysis of commercial production lots of 
RDX and These experiments have 

been described in Section 1.2. 

COXCLUDING ReMAEKS 

During the chromatographic studies of smokeless 
powders and related substances, many phenomena 
and relations were observed which are of interest and 
value in the general application and theory of chroma- 
tography. Because these matters were not of primary 
concern, however, the observations pertaining to them 
were usually only incidental. 

First, the relative chromatographic positions of 
many similar compounds were considered, and some 
observations were made on the relation between the 
structure of a compound and its adsorption affinity 
on silicic acid. It was soon noted that the adsorption 
affinity of one compound relative to another is often 
a function of the type of developer which is employed ; 
frequently it is possible to produce an inversion in 
the positions of two substances by a change in the 
type of developer. Later it was discovered that the 
position of one compound relative to another can 
often be changed merely by an alteration in the de- 
veloping strength of a developer without any change 
in the nature of the components of the developer; 
this appears to be related to a phenomenon which has 
been termed the ^Threshold effect. Finally, a num- 
ber of instances were found in which a presumably 
homogeneous compound produced two distinct and 
separate zones on the chromatographic column under 
certain specified conditions. Although some examples 
of this anomalous ‘hlouble zone effect’’ could ap- 
parently be explained in various ways, others defied 
all interpretation. 

6 12 STABILITY OF PROPELLANTS* 

Studies of the stability of propellants by Division 
8 divide themselves into two parts : studies of double- 
base powders at the California Institute of Tech- 

*The discussion of the stability program at the California 
Institute of Technology is taken from a summary prepared by 
Jerry Donohue, William N. Lipscomb, John W. Otvos, and 
David P. Shoemaker. 


nology and studies of other propellants at the Ex- 
plosives Research Laboratory. There was so little 
overlapping of these two programs that they are best 
discussed separately. We shall begin with the work 
of the Explosives Research Laboratory. 

Surveillance studies over a period of two and a 
half years showed that solvent-extruded composite 
propellants (Section 6.2) and powders related to 
Albanite (Section 6.7) had more than adequate sta- 
bility for military purposes. It was shown further 
that the results of the 65 C surveillance corresponded 
well with practical observation of powder stability. 
Analyses of the stabilizer content of samples under 
surveillance gave useful estimates of the life of the 
powder. By contrast, the 120 C and the 135 C thermal 
stability tests and the Bergmann- Junk tests were of 
little usefulness.'^®*^^^ 

A theoretical treatment has been made of adiabatic 
ignition. The theory predicts the rate of self-heating 
of an explosive for which kinetic constants on decom- 
position are available. Since the rate constant and 
activation energies were available from gas evolution 
measurements for NEXO and MXO, it was possible 
to calculate the ignition times of these explosives 
under adiabatic conditions; the calculated and ex- 
perimental results agreed Avell. The theory accurately 
predicted the entire time-temperature curves for the 
self-heating of these explosives. 

The test was then applied to solvent-extruded com- 
posite propellants, and to powders which contain 
stabilizer. (Unless stabilizer is present the decom- 
position is autocatalytic, and the equations for adia' 
batic ignition do not apply.) In the absence of auto- 
catalysis' a powder cannot decompose faster than it 
will under strictly adiabatic conditions. The results 
of adiabatic ignition experiments, therefore, permit 
a calculation of the minimum life of a powder under 
any conditions, provided only that stabilizer is present. 

The program of studies of the stability of smoke- 
less powder at the California Institute of Technology 
included the development and extensive application 
of chromatographic - spectrophotometric techniques 
for the measurement of the amount of stabilizer and 
of the transformation products of stabilizers in double- 
base powder, the development of a technique for the 
application of the vacuum stability test to the ex- 
amination of small samples of double-base powder, 
the development of a highly modified form of the 
Taliani-type test, and the development of a standard 
procedure for making pH measurements on double- 
base powders. In addition, preliminary experiments 


|( n,\ FI 


STABILITY OF PROPELLANTS 


135 


were made leading to the develoi)meiit oi* other sta- 
bility tests : a test based on the interaction ol‘ powder 
and nitrogen dioxide at room temperature, a rocket 
safe test, and a test for ‘hivailahle nitrite” in double- 
base i)owder. 

One result of this program was the accumulation 
of a large quantity of new data relating to the sta- 
bility of single-base and double-base powders having 
a wide variety of compositions. For example, vacuum 
stability tests were made on over 500 powders of 
which over *200 were pilot lots^®^’ of rocket propellants 
which were submitted hy the Army and Navy. Other 
investigations showed that there was no correlation 
between the stability and the color changes under- 
gone by a certain powder, and that powder made from 
100^ rework was as stable as that made without 
reworked material. 

The results of all these stal)ility tests are sum- 
marized briefly in the following ten subsections. 

Consecutive Transformation of 
Diphenylamine in Double -Base Powder 

A systematic investigation of the consecutive trans- 
formation of diphenylamine in double-base powder 
upon storage at surveillance temperatures was carried 
out using the chromatograpliic-spectropliotometric 
analytical techniques described in Section 6.11. The 
results of this study, and an extended discussion of 
them have been presented in a formal report^^® deal- 
ing with the stabilization of smokeless powder by 


diphenylamine; they are briefly summarized in the 
following paragraphs. 

Samples of JP 201:, a ballistite stabilized with 
diphenylamine, were stored at 71 C for various peri- 
ods of time up to over 174: days. As the samples were 
removed from storage, analyses were made for di- 
phenylaniine and all of its nitro and nitroso deriva- 
tives which had been previously detected in artificially 
aged ballistite. These analyses accounted for only 50 
to 60 per cent of the original diphenylamine content of 
the powder; the fate of the remaining diphenylamine 
is not known. The heating also resulted in the forma- 
tion of dark-colored pigments, at least one of which was 
shown to be related to diphenylamine blue. The analy- 
tical data which were obtained by chromatographic- 
spectrophotometric methods are shown in Table 7. 

A schematic representation of reactions which 
might be involved in the consecutive transformation 
of nitroso and nitro derivatives of diphenylamine is 
shown in Figure 10. 

A mathematical treatment of the reactions involved 
in the consecutive transformations of diphenylamine 
was carried out on the assumption that they consti- 
tuted a system of pseudo first-order reactions." For 
the details of the mathematical analysis, see refer- 

"A system of pseudo first-order reactions may be defined as 
one in which a set of consecutive and competing reactions 
which do not follow the first-order law may nevertheless be 
amenable to the mathematical treatment for first-order re- 
actions provided the effective first order rate constants, al- 
though themselves not constant, have constant ratios to each 
other. 


Table 7. Derivatives of diphenylamine isolated from grains of ballistite JP 204 during storage at 71 C.* 


Duration of heating (days) 

0 2 4 8 20 35 48 82 124 174 258 

^ A ^ ^ A ^ 

Yellow Red Yellow Red 


Content of: 


Diphenylamine 

7.11 

4.27 

1.60 

0.0 

t 









N-NO-DPA 

0.42 

2.08 

3.55 

4.47 

2.35 

0.78 

0.18 

0.01 






2 -NO 2 -DPA 

0.08 

0.13 

0.10 

0.31 

0.24 

0.09 








4 -NO 2 -DPA 

0.02 

0.07 

0.09 

0.14 

0.35 

0.18 

0.04 







N-NO- 4 -NO 2 -DPA 




0.45 

0 96 

0.21 








2,2'-diN02-DPA 




0.04 

0.29 

0.45 

0.42 

0.04 






2,4'-diN02-DPA 




0.19 

1.01 

1.51 

0.95 







4,4'-diN02-DPA 




0.06 

0.56 

0.83 

0.47 







2,2',4-triN02-DPA 




0.02 

0.16 

0.67 

1.36 

2.08 

1.84 

0.06 




2,4,4'-triN02-DPA 




0.01 

0.34 

1.57 

3.21 

2.18 

0.01 





TetraN02-DPA 






0.07 

0.23 

3.51 

7.52 

2.75 

0.57 

0.31 

0.45 

PentaN02-DPA 









0.09 

2.40 

0.75 

0.91 

0.80 

HexaN02-DPA 










4.75 

6.25 

6.13 

5.96 

Picric acid 










0.16 

0.0 

0.18 

0.25 

VVt DPA equiv to sum of cpds 

7.55 

6.24 

4.79 

4.68 

4.65 

4.12 

4.03 

4.10 

4.70 

4.37 

3.01 

3.04 

3.05 


♦Results are expressed in milligrams of each compound isolated from one gram of powder. 
fWhere no value is given the quantity is less than 0.01 mg. 


(^XFI I)I':^T1AL1 


136 


PROPELLANTS 



OPA - DIPHENYLAMINE 

N - N - NUROSO - DPA 

2 - 2 - NITRO - DPA 

4 - 4- NITRO - DPA 

N2 - N- NITROSO - 2 - NITRO - DPA, ETC 
TETRA - 2, 2^4, 4'- TETRANITRO - DPA 
PENTA - 2, 2^4,4^, 6- PENTANITRO - DPA 
HEXA - 2, 2^, 4, 4'. 6, 6^- HEXANITRO - DPA 
PA - PICRIC ACID 





♦- 


DIRECT NITRATION 

N- NITROSATION AND DENITROSATION 
REARRANGEMENT AND OXIDATION OR OXIDATION 
AND REARRANGEMENT 

NITRATION ACCOMPANIED BY DENITROSATION 



OTHER REACTIONS 

ISOLATED FROM JP 204 SHEET, BUT NOT 
FROM GRAIN 

NOT YET ISOLATED FROM ANY POWDER 


Figure 10. Possible relations among diphenylamine derivatives. 


PIGMENTS AND UNRECOVERED DERIVATIVES, INCLUDING PRODUCTS OF COMPLETE OXIDATION 



STABILITY OF PROPELLANTS 


137 


eiice 120. The procedure I'or evaluating the rate 'con- 
stants involved the assumption ol a set ot constants, 
the calculation oi' the resulting expressions for the 
concentrations of the various diphenylaniine deriva- 
tives, a comparison of the corresponding curves with 
the experimental data, and the estimation of the 
corrections necessary to improve the agreement be- 
tween the theoretical curves and the experimental 
points. This procedure was repeated until satisfactory 
agreement was obtained. A comparison of the theoret- 
ical curves thus obtained and the experimental points 
is presented in Figures 11 and 12. From the results 
of this treatment it was possible to obtain information 
relating to the relative reactivities in the powder of 
the substances responsible for the nitrosation and 
nitration of the stabilizer. 

In addition to these studies on dP 201, a series of 
studies was made on powders in which various de- 
rivatives of di})henylaniine had been incor})orated as 
stabilizers. These powders were stored at 71 C, and 
chromatographic-S])ectrophotometric analysis were 
made to determine the apparent uniniolecular rate 
constant for the • disappearance of the stabilizer. By 
comparison of these rate constants with those obtained 
from the corresponding compounds in JP 201 it was 
possible to make an estimate of the relative concentra- 
tion of nitrating agent involved in reactions with 
these various stabilizers. 

These investigations have tremendously increased 
our knowledge of the fate of the stabilizer in a bal- 
listite or similar powder. However, even these ex- 
tensive analytical data do not necessarily provide a 
decisive answer to questions concerning the absolute 
stability of a powder or the relative merits of dif- 
ferent stabilizing compounds. In most cases there is 
no way of interpreting them in terms of the impor- 
tant changes which take place in the explosive con- 
stituents of the powder. Nevertheless, in powders of 
comi)arable composition containing initially the same 
concentration of a given stabilizer, a comparison of 
the rates of consecutive transformation of the sta- 
bilizer may yield valuable information. The presence 
of an undesirable constituent which promoted the de- 
composition of the nitric esters might be indicated 
by the more rapid rate of transformation of the sta- 
bilizer in one powder than in another containing the 
same initial percentage of the same stabilizer. 

Bather extensive discussions of the problems in- 
volved in the determination and comparison of the 
stabilities of powders are given in two formal re- 

ports.^20.183 


Studies of Stabilizer Depletion in 
Heated Powders 

Many ex})erimental studies involving the deple- 
tion of the stabilizer in powders during accelerated 
aging at elevated temperatures, were made with the 
use of chromatographic - spectrophotometric tech- 
niques. 

In oiie of these series of experiments, samples of 
ballistite JP 20-1 Avere stored at various temperatures 
(80, 00, 100, and 110 C), and samples w'ere remoA'ed 
after various times for chromatographic-spectropho- 
tometric determinations of the content of stabilizer 
and several of its immediate transformation products. 
These data Avere obtained in order to supplement the 
experimental results of the investigations described 
in the preceding section. A similar series of experi- 
mental studies AA’ere made on an FNH poAvder, Bad- 
ford Pilot Lot No. 141, Avhich had been stored at 
90 and 100 C. Simple mathematical treatments, sim- 
ilar to those discussed above have been carried out for 
these initial reactions in the transformation of di- 
phenylaniine.^^® The postulates on aaIhcIi this mathe- 
matical treatment Avas based are (1) that the reaction 
by Avhich diphenylaniine is consumed Avhen smoke- 
less poAvder is heated is first order AAutli respect to 
diphenylaniine, and (2) that the diphenylamine is 
consumed by a nitrating-nitrosating agent, the exact 
nature of Avhich is unknoAvn but AA’hose concentration 
varies linearly Avith the time of heating, according to 
the equation C = a l)t, Ailiere a and h are constants 
and t is the time of heating. Although this treatment 
could lie considered to have only approximate validity, 
it Avas possilile to choose the constants in the result- 
ing equations so that the agreement betAveen calcu- 
lated values and the experimental points AA^as satis- 
factory. The results of this treatment suggested that 
the reaction by Avhich diphenylaniine is consumed in 
ballistite JP 204 differs only in rate from that in 
FNH poAvder BPL 141. From the results of tests 
on a series of poAvders containing varying percentages 
of diphenylaniine it seems likely that diphenylaniine 
is cajiable of direct reaction Avith one or more of the 
constituents of smokeless poAvder, at least in the range 
of temperature at Avhich the tests Avere carried out. 

A simplified mathematical analysis^®^ Avas also ap- 
plied to the initial reactions of a typical centralite- 
stabilized poAvder, Badford Pilot Lot No. 142, Avhich 
had been heated for various lengths of time at 65, 
75, and 110 C. The assumptions on AAdiich this treat- 
ment Avas based are that the reactions by Avhich 4- 


rr'oyFlUKNTTXTTj 


138 


PROPELLANTS 


o 

UJ 

tn 

v> 

ui 

a: 

a. 

X 

iij 


I 

o 

< 

UJ 


»- 

I 

o 



Figure 11. Transformation of diphenylamine in grains of ballistite JP 204 stored at 71 C. Comparison of theroretical 
curves with experimental data. 



Figure 12. Transformation of diphenylamine in grains of ballistite JP 204 stored at 71 C. Comparison of theoretical 
curves with experimental data. R denotes red samples; the other samples were yellow. 


(( UM J LitvNTlAI. 1 


STABILITY OF PROPELLANTS 


139 


nitroceiitralite and N-nitroso-N-etliylaiiiliiie are 
formed from centralite, are first order with respect 
to eentralite and that the depletion of 4-nitrocen- 
tralite is first order with respect to its concentration. 
It was possible to choose the constants in the result- 
ing equations to give theoretical curves which gave 
satisfactory agreement with the experimental points 
as determined by chromatographic-spectrophotometric 
analyses of the samples. The results also indicated 
that at lower temperatures a smaller fraction of the 
eentralite was converted to 4-nitrocentralite than at 
higher temperatures. 

6.12.3 Vacuum Stability Test 

The vacuum stability test for explosives, which was 
devised by Farmer, depends upon the fact that 
many explosives (particularly those which are nitric 
esters) slowly decompose, evolving gases, when they 
are heated in evacuated containers at elevated tem- 
peratures. The extension of this test to investigations 
of smokeless powders was carried out with the use 
of apparatus patterned after that of McGill. 

The experimental procedures and the results of 
these tests have been presented in several formal 
OSKD reports.^^-^««-'»^ 

In the vacuum stability test the powder sample (0.1 
to O.o g) is heated in the sample tube of the apparatus 
shown in Figure 13, and the volumes (at STP) of 
the gas evolved after various times of heating are 
calculated from readings of the pressure which are 
made on the attached capillary manometer; the latter 
is maintained at room temperature, ^lost of the tests 
were made at 110 C; additional tests were also run 
at temperatures ranging from 80 to 120 C in order 
to provide a basis for extrapolation of the results 
to lower temperatures. 

The results of the vacuum stability tests indicated 
that lower average rates of gas evolution are shown 
by the following powders. 

1. Powders containing carbazole, ^ - nerolin, 
ethyl eentralite, or nitro derivatives of diphenylamine, 
as compared with those containing diphenylamine. 

2. Powders containing lower percentages of ethyl 
eentralite or diphenylamine, as compared with those 
containing a higher percentage of either of these 
compounds. 

3. Powders containing ethylphenylurethane or di- 
phenylurethane, as compared with those containing 
comparable percentages of acardite. 

4. Powders containing nigrosine, as compared with 
tho.se eontaining carbon black or no darkening agent. 


5. Double-base powders containing dinitrotoluene, 
as compared with those containing approximately the 
same percentage of trinitrotoluene. 

6. Powders containing a higher ratio of nitrocel- 
Inlose to nitroglycerin, as compared with those having 
a lower ratio. 

7. Powders containing diethyleneglycol dinitrate 
in place of a comparable percentage of nitroglycerin. 





Figure 13. Standard-taper units for vacuum stability 

tests. 

8. Powders containing a large percentage of potas- 
sium perchlorate (EJ powders), as compared with 
standard double-base powders. 

0. Double-base powders containing RDX, Fivonite 
or 1)1 NxA, as compared with those containing cor- 
responding percentages of nitroglycerin. 

10. Pyro or FNH single-base powders, as compared 
with standard double-base powders. 

11. Standard double-base powders, as compared 
with those containing manganese dioxide. 

12. Powders containing potassium sulfate or no 
salt, as compared with those containing potassium 
nitrate. (This difference is especially great.) 

13. Powders containing no salt, as compared with 
those containing potassium sulfate or sodium ehloride. 
(These differences are small.) 


140 


PROPELLANTS 


14. Powders containing alkaline earth nitrates as 
compared with those containing alkali nitrates. 

The rate of gas evolution appears to be unaffected 
by the addition of small percentages (0.1^) of lead 
stearate or candelilla wax. 

The addition of small quantities of inorganic salts 
to double-base powder was found to increase its rate 
of gas evolution : potassium nitrate promoted gas evo- 
lution more strongly than almost any other salt ex- 
amined; potassium sulfate ordinarily had little or no 
effect. The magnitude of the effect depended to a 
considerable extent on the nature of the particular salt 
added, i.e., different salts having the same anion or ca- 
tion, the same valence type, etc., often produced widely 
different effects. The data obtained from powders con- 
taining various concentrations of inorganic salts sug- 
gested the hypothesis that the magnitude of the effect 
also depends on what may be called the active concen- 
tration, or soluhility, of the salt in the powder, a 
quantity which is approximately equal to or less than 
the gross concentration. It also seemed probable that 
potassium nitrate, and perhaps other salts as well, 
enter catalytically into the gas evolution reactions. 

Diphenylamine exerted a powerful inhibitory 
effect on gas evolution in the vacuum stability test as 
long as it was present in the powder, but the disappear- 
ance of this compound was accompanied by a normal 
or slightly higher rate of gas evolution. 

A study of the property of ureas substituted with 
various combinations of ethyl and phenyl groups 
showed that the N,N'-diphenyl configuration may be 
associated with the greatest inhibitory effect on gas 
evolution in the vacuum stability test at 110 C. 

The gases evolved from double-base powder during 
the vacuum stability test were analyzed ; they consisted 
chiefly of carbon dioxide, nitric oxide, carbon monox- 
ide, nitrogen, and nitrous oxide.^®'"^ The composition 
of the gases varied considerably with both the tempera- 
ture and the duration of the test. 

The presence of water, acid, and nitroglycerin was 
demonstrated in the products which collected in the 
cooler portions of the vacuum stability units. 

Special attention was given to a critical evaluation 
of the results of the vacuum stability as compared with 
other standard and special tests. The vacuum stabil- 
ity test, in common with several standard tests which 
are used to evaluate the stability of smokeless powder, 
possesses the disadvantage that it is carried out at 
temperatures which are considerably a])ove normal 
storage conditions and the special disadvantage that 
there is a marked tendency for the products of decom- 


position of the powder to distil into cooler portions of 
the unit and thus be removed from farther interaction 
with the sample. 

^ The Taliani-Type Test 

In the Taliani test the powder sample is heated at 
constant volume in an initial atmosphere of air at 
atmospheric pressure, and the pressure which develops 
during the test is recorded as a function of the time 
of heating. A highly modified form of the Taliani ap- 
paratus was developed at the California Institute of 
Technology. The apparatus, experimental procedure, 
and some of the results obtained have been de- 
scribed. Preliminary results indicate that this form 
of the Taliani test is suitable for routine testing of 
smokeless powder and that it may possess considerable 
advantage over the vacuum stability test in the evalu- 
ation of the relative stability of powders. 

6.12.5 Measurements of pH 

It has long been known that under ordinary storage 
conditions smokeless powders undergo gradual changes 
in composition and properties, often leading eventually 
to deterioration beyond the range of safe or effective 
use. It has also been known that these changes are 
accompanied by the development of acidity in the 
powders. A technique for the detection and measure- 
ment of this acidity would therefore be expected to 
be valuable in furnishing information relating to the 
stability of smokeless powders. Many such techniques 
have been proposed and applied. In general they have 
either made use of chemical indicators^®^’^®^’^®® or have 
involved the potentiometric estimation of hydrogen- 
ion concentration in a solution prepared from the 
powder sample. 

The method developed at the California Institute of 
Technology for studying the acidity of powders is 
based on the potentiometric method.^®^ The pH of a 
suspension obtained when a given amount of water is 
added to an acetone solution of a powder sample is 
determined with a Beckman (Model G) pH meter. 
Tlie method is more fundamental than many proposed 
earlier because the powder is completely dispersed dur- 
ing the course of the procedure. It is more flexible 
in its application because it prescribes no previous 
treatment for the powder sample. Furthermore, it is 
important to note that all operations relating to this 
test arc performed at room temperature; in this re- 
spect it differs from the usual stability tests carried 
out on single- and double-base powders. 


STABILITY OF PROPELLANTS 


141 


Some of the results obtained from the measurements 
of pH are summarized in the following paragraphs. 

Captured German and Japanese propellants showed 
pH values which were considerably higher than those 
of standard U. S. powders. ^lost German propellants 
have values of a])out 8.0, Japanese propellants about 
6.5, and U. S. propellants about 5.5 to 6.0. As a rule 
the foreign powders were found to contain significant 
amounts of alkaline earth elements.^"®’^®^ It is very 
likely that their high pH values were due in large 
part to the presence of alkaline earth oxides or car- 
bonates. 

Measurements of pH were made on a group of modi- 
fied ballistites^*’® after various periods of heating at 
65.5 and 71.0 C. All of the ballistites became increas- 
ingly acidic during storage at elevated temperature. 
Those which contained potassium nitrate showed lower 
pH values at all corresponding times of heating than 
did similar powders containing potassium sulfate. In 
those powders which contained potassium sulfate the 
substitution of diphenylamine for ethyl centralite 
seemed to increase the rate of decline of the pH value. 

An examination of the effects of powder composi- 
tion on pH value shoAved that most powders containing 
potassium nitrate showed lower pH values than pow- 
ders of similar composition containing potassium sul- 
fate. The reason for this effect is not Avell understood. 

The stabilizers Avhich Avere examined had no marked 
effect on pH value. 

In connection Avith the study of foreign propellants 
it Avas noted that those poAvders Avhich contained nitro- 
glycerin Avere always more acidic than similar ones 
containing diethylene glycol dinitrate. 

The nitrocellulose ingredient occasionally had a 
marked effect on the pH value of a poAvder, possibly 
because of some special treatment that the nitrocel- 
lulose had undergone. 

It thus appears quite likely that the source and 
purity of poAvder ingredients are often the controlling 
factors in determining the pH value of poAvders. For 
this reason a measurement of pH alone cannot be in- 
formative, and therefore the pH test must be coupled 
Avith other stability tests to be most useful. 

6.12.6 Surveillance Test 

The suiweillance test at 65.5 C is a standard test 
in use by the Army and Navy for the estimation of the 
stability of propellent poAvders. In this test a forty- 
five-gram sample of the poAvder in a glass-stoppered 
bottle of a standard design is placed in a room or oven 
that is maintained constantly at a temperature of 


65.5 C, and the sample is examined daily until red 
fumes are observed in the bottle, or until a specified 
minimum time has elapsed. This time in days is 
reported as the 65.5 C surveillance life of the pro- 
pellant. 

If this test is to be used as a means for detecting 
small differences in the relative stabilities of samples 
of poAvder, it is essential that all specimens be 
subjected to conditions AAdiich are as nearly identical 
as possible throughout the test. For this purpose a 
surveillance house AA^as designed and constructed AAdiich 
provided for all samples storage conditions as nearly 
identical as practicable.^®"^ The house accommodates 
1,000 bottles Avhich are attached to a single endless 
chain lielt AAdiich travels sloAvly on sprocket AAdieels over 
tAvo concentric helical paths. The bottles are examined 
through a AvindoAv located near the chain and can be 
introduced or removed through small access ports. 

The great disadvantage of the surveillance test, par- 
ticularly in experimental studies, is the length of time, 
sometimes amounting to a year or more, that is usually 
required for the completion of the test. Consequently 
many results of tests on poAvders of various composi- 
tions tested at the California Institute of Technology 
are not yet available. From the tests already com- 
pleted,^*^ hoAA^ever, the folloAving conclusions AA'ere 
reached. 

PoAvders containing diphenylformamide shoAA'ed 
short surveillance liA^es (34 to 62 days). Powder con- 
training no stabilizer at all shoAved an extremely short 
surveillance life (14 days), in agreement Avith gen- 
eral experience. 

Nitroglycerin poAvders containing ethyl centralite 
shoAA^ed, in general, longer surveillance liA^es than anal- 
ogous poAvders containing diphenylamine. Moreover 
an increase in the amount of centralite in a powder Avas 
found to prolong its surveillance life. Powders con- 
taining potassium nitrate shoAA^ed shorter surveillance 
lives than poAvders containing potassium sulfate, and 
increases in the content of potassium nitrate resulted 
in decreases in surA^eillance life. 

^ The Heat Test 

The results of heat tests-®^’-®® on double-base poAv- 
ders^®^ are in reasonably good agreement Avith the 
results obtained for the same powders in the vacuum 
stability test. The unusually long heat test times shown 
by poAvders containing nitroguanidine and either Fi- 
vonite or DINA may be due, in part, to the differences 
in composition of the gases evolved by these poAvders 
and by the more common double-liase poAvders. 




142 


PROPELLANTS 


6.12.8 Nitrogen Dioxide Stability Test 

Some preliminary experiments were made on a sta- 
bility test based on the reaction of nitrogen dioxide 
at room temperature with douhle-base powder. When 
a sample of powder was placed in a flask which con- 
tained a small concentration (about 25 mg per liter) 
of nitrogen dioxide, the concentration dropped rapidly 
to a very low value (0.1 mg per liter) and suhsequently 
rose, at first slowly and then rapidly. Measurements^ 
of the concentration were continued at regular time 
intervals until a high value was reached (10 mg per 
liter or more). 

Although an examination of the preliminary data 
which were obtained suggested that the behavior of 
smokeless powder, when treated with nitrogen diox- 
ide, may be made the basis of a stability test, much 
more work must be done before definite conclusions 
can be drawn. If successful, this test would possess the 
advantage that it could be performed quickly and that 
the powder would be at normal storage temperatures 
throughout the test. 

I 

6.12.9 I^ocket Safe Test for Shipboard Use 

At the request of the Navy Bureau of Ordnance, 
the development was undertaken of a means by which 
dangerous decomposition of a propellent charge in a 
rocket motor might be easily and quickly detected on 
shipboard or in the field. It was desired that the test 
he applicable to a rocket motor without destroying the 
usefulness of the round, that it he a test which un- 
trained personnel on shipboard could perform and in- 
terpret, that it he applicable to all rocket motors in 
service, and that it make use of no indicators that are 
unable to withstand the severe conditions under which 
a shipboard test would ordinarily be used. 

An unsuccessful attempt was made to develop a 
test based on measurements of the electrical conductiv- 
ity of powder samples. A test that made use of the 
tarnishing of steel disks when they are exposed to 
fumes evolved by decomposing powder was investi- 
gated, hut work on it was abandoned because the use 
of this test for every round would require the installa- 
tion of an observation window in every rocket motor. 
Another test, which was partially investigated and 
which appeared to he promising, involved the with- 
drawal of a sample of gas from the rocket motor and 
the detection of gaseous decomposition products of the 

'"The concentration measurements were made by means of a 
conductometric apparatus (“Egbert”) which was developed 
by NDRC, Division 9. 


powder by bubbling the sample of the gas through a 
suitable indicator solution. 

The test that was most extensively investigated de- 
pended upon the breaking of an electric circuit when 
corrosive fumes from powder undergoing decomposi- 
tion severed a fine copper wire. An insulated unit 
carrying the wire is mounted in a hole in the nozzle 
closure of the rocket motor. External leads are pro- 
vided for testiiig the circuit with a suitable indicating 
device. 

A rough calibration of this test device was made by 
exposing it to known concentrations of nitrogen di- 
oxide at different temperatures and different relative 
humidities. Preliminary experiments were made with 
stable and unstable powders, and several standard 
rocket rounds were fitted with the device for observa- 
tion during normal storage. 

When the investigation was terminated, much ex- 
perimental work remained to he done before the 
copper wire safe test device could he recommended 
for routine use.^®® 

6.12.9 Estimation of Available Nitrite 
in Smokeless Powder 

Since the gases evolved by powders at elevated tem- 
peratures are known to contain various reduction 
products of nitrate, such as nitric oxide, nitrous ox- 
ide, and nitrogen, it might he expected that the 
heated powders themselves would contain nitrite ion 
or would yield nitrite ion when extracted with water. 
SiK'h is indeed the case, and a procedure was worked 
out for the estimation of “available nitrite^’ in heated 
and unheated samples of double-base powder. Al- 
though it was not expected that the amount of avail- 
able nitrite detected would be strictly equivalent to 
the amount of nitrite ion actually present in the pow- 
der, the available-nitrite content might perhaps give 
a relative measure of the extent of decomposition of 
the powder. 

The procedure for the available-nitrite determina- 
tion is based on a colorimetric method which is re- 
producible and is sensitive to about 0.3 part of nitrite 
per million parts of powder.^®® 

Preliminary results indicate that the available- 
nitrite content of unheated, normal powder is not 
much greater than the limits of detectibility of the 
method, but that for heated samples of powder the 
nitrite content may he 1,000 times greater than for 
the uidieated samples. 


THE PHYSICAL PROPERTIES OF SMOKELESS POWDERS 


143 


6.13 the physical properties of 
SMOKELESS POWDERS- 

In World War II, interest in the mechanical prop- 
erties of smokeless powders has been greatly accen- 
tuated by the use of these propellants in rockets and 
similar devices, which has introduced quite new re- 
quirements as to strength and related characteristics. 
Knowledge regarding the effect of various factors 
upon these properties is even yet rather limited, since 
no complete and systematic investigation of this sub- 
ject has previously been made. Many useful investiga- 
tions were made in various laboratories of the effect 
of moisture content, of the effect of varying the 
amount of rolling, etc., but studies of the effect of 
composition have generally not been of the sort which 
would be expected to yield very fundamental informa- 
tion. For obvious reasons, such studies have usually 
been concerned with powder series in which only 
such changes were made as are compatible with a 
roughly constant potential. Unfortunately more than 
one factor has generally been varied at a time so that 
the results have been difficult of interpretation, and 
the general situation has not been clarified. 

Since it seemed desirable to obtain more funda- 
mental information regarding the effect of composi- 
tion upon the mechanical properties of smokeless 
propellants, measuring equipment was developed at 
the California Institute of Technology under OSRD 
Contract OEMsr-881, and a program of investigation 
was laid out along lines described below. It seemed 
unprofitable for this laboratory to be concerned with 
structural factors involving particular shapes of pro- 
pellent charges and their relation to the container or 
rocket motor. Studies of this sort were made in other 
laboratories, and it’ is understood that satisfactory 
progress was made in this direction. The object was 
rather to investigate those intrinsic properties of the 
propellant of which a knowledge might be of use in 
any future design work. The properties chosen for 
immediate study were hardness, as measured by the 
methods developed by A. G. Ward and co-workers,^^® 
and the so-called Y^oung’s modulus, or more exactly, 
the compression under a fixed load and subsequent 
recovery as a function of time. 

A single apparatus was constructed which per- 
mitted the measurement of either hardness or Young^s 
modulus merely by exchanging ‘^anvils” and adjust- 
ment of the loading mechanism. The apparatus was 

-This section is taken from a summary prepared by Richard 
M. Badger. 


designed to make measurements upon Yi-in. or %-in. 
rod for the following reason. A systematic investiga- 
tion may be presumed to require the study of a large 
number of special compositions which would be diffi- 
cult to procure in large quantity. Measurements were 
consequently made upon materials extruded by the 
small press which is designed to deal with small ex- 
perimental batches prepared at the California In- 
stitute of Technology (see Section 6.10). 

It was the intention to study, so far as is possible, 
the effect of varying separately the various factors of 
composition which may be expected to affect the phys- 
ical properties of a propellant. These factors were 
varied within sufficiently wide limits so that the 
resulting effects were well outside the limit of experi- 
mental error. The majority of powders of any given 
series were presumably impractical from the point 
of view of ballistics, but it was anticipated that by 
this procedure the situation would be more rapidly 
clarified than would be the case if one had attempted 
to keep within the range of practical compositions. 

The phase of the investigation chosen for first study 
was the 'effect of the character of the nitrocellulose 
upon the physical properties of the propellant. In 
particular the following factors were studied: the 
effect of the source of the cellulose, whether wood 
pulp or cotton linters; the effect of varying the vis- 
cosity or average molecular weight of the nitrocel- 
lulose (the nitrogen content being kept constant) ; 
the effect of varying the nitrogen content of the nitro- 
cellulose (the viscosity being kept constant) ; the 
effect of blending materials of different nitrogen con- 
tents and viscosities. This last phase was essentially 
a study of the effect of the heterogeneity of the nitro- 
cellulose upon the properties of the propellant. The 
following blends were selected for investigation : a 
blend of high and low viscosity components having 
the same nitrogen content; a blend of high and low 
nitrogen components having the same viscosity; a 
blend of high nitrogen, high viscosity material with 
a second component of low nitrogen content and high 
viscosity; a blend of high nitrogen, high viscosity 
material with a second component of low viscosity 
and low nitrogen content. These blends were com- 
pared with homogeneous material having the average 
viscosity and nitrogen content of the blend. Blends of 
high nitrogen, low viscosity nitrocellulose with mate- 
rial of low nitrogen content and high viscosity would 
have been added to this list if suitable nitrocelluloses 
could have been obtained. 

Several series of experimental powders embodying 


(('■oxrinKN'i'iTrr) 


144 


PROPELLANTS 


the variations mentioned above were prepared for 
study. These were all made according to the JPH 
formulation given below and differed only in respect 
to the nitrocellulose constituent. 


Formulation of Experimental 

Powders 

Nitrocellulose 

54.5 

Nitroglycerin 

43.0 

Ethyl centralite 

1.00 

Potassium sulfate 

1.50 

Carbon black (added) 

0.20 


Considerable time was devoted to establishing the 
conditions under which measurements were to be 
made and to determining a suitable routine of meas- 
urement. Any conditions of measurement chosen had 
to be somewhat arbitrary, but it was desirable, both 
that ‘they be practical of attainment, and that they 
have some relation to the conditions under which 
propellants are normally conditioned and employed 
in practice. It was tentatively decided to make routine 
measurements at25C (77 F), and at 45 C (113 F) on 
powder samples which were adequately conditioned at 
50 per cent relative humidity at 25 C. Powder sam- 
ples to be measured at the higher temperature were 
brought to temperature under conditions such that 
loss of volatiles was presumed to be negligible. A 
provisional routine of measurements was worked out 
which appeared to be suitable for the materials under 
investigation. 

These investigations provided many interesting re- 
sults, but any conclusions arrived at are tentative. 
With one possible exception, the measurements of 
hardness and Young’s modulus were found to run 
parallel. Because of lack of time for study of the 
data, no precise correlation was made. The most strik- 
ing observation made is the extreme sensitivity of 
the mechanical properties of the propellant to the 
nitrogen content of the nitrocellulose. This sensitivity 
is so great that it may well contribute to the lack of 
perfect reproducibility of measurements from sample 
to sample. The effect of varying the viscosity of the 
nitrocellulose constituent was not very striking ex- 
cept in the I'ange of very low viscosities. The effect 
of blending nitrocelluloses of different characteristics 
is not as yet entirely clear. In general the powders 
made from blended materials appeared to be some- 
what harder at 25 C than those made from more 
homogeneous constituents, but they tended to have 
larger temperature coefficients of their physical pro])er- 
ties. ddie effect of wood pulp versus cotton linter nitro- 
cellulose was not definitely established at ordinary 


temperatures, but the wood-pulp material resembled 
a blend in respect to the temperature coefficient. 

The investigations here briefly described are being 
continued at the California Institute of Technology 
under Contract NOrd-9652 with the Bureau of Ord- 
nance of the Navy Department, and full reports will 
be given of the results obtained when various stages 
of the investigation are completed. It is expected that 
later studies will include the effect of the ratio of 
nitroglycerin to nitrocellulose, the effect of DEGN 
versus nitroglycerin, and the effect of plasticizers in 
relation to the nitrogen conteiit of the nitrocellulose. 

6 14 EXAMINATION OF FOREIGN 
PROPELLANTS^ 

From time to time the group working on Contract 
OEMsr-881 at the California Institute of Technology 
was requested to analyze samples of explosive mate- 
rial taken from captured rounds of German and 
Japanese ammunition. Most of these samples were 
propellent powders taken from rocket motors; a few, 
however, consisted of high-explosive materials taken 
from the warheads of shells and rockets, while other 
samples consisted of propellent powders for guns. 
The very unusual compositions of the rocket propel- 
lants and their excellent physical properties and burn- 
ing characteristics provided opportunities for inves- 
tigating the relationships between the composition 
and the properties of double-base powders and sug- 
gested possible methods of formulating rocket pro- 
pellants superior in physical and burning properties 
to those now commonly used in U. S. rockets. 

The foreign rocket and gun propellants were ana- 
lyzed qualitatively and quantitatively for their major 
constituents, the nitrocellulose blends were examined, 
and the inorganic constituents were estimated. Sev- 
eral rocket propellants were examined with the micro- 
scope to obtain information concerning the methods 
of manufacture and were subjected to vacuum sta- 
bility tests and measurements of pH. Their linear 
burning rates were measured at various temperatures 
and pressures and were compared with those of rep- 
resentative U. S. rocket propellants. The composi- 
tions of some of the propellants were used as starting 
points for the formulation and preparation of experi- 
mental powders in small batches of rolled sheet and 
dry-extruded grain; these experimental powders were 

^This section is taken from a report submitted by David 
P. Shoemaker. 


I;OyriDESTL\L\ 


EXAMINATION OF FOREIGN PROPELLANTS 


145 


also subjected to tests in order to determine the extent 
to which the excellent physical and burning properties 
of the German and Japanese propellants were repro- 
duced in these powders. 

The results of these investigations have been de- 
scribed in OSRD reports.^®®’^^^^’^^^ The principal fea- 
tures of the work, chiefly with regard to the foreign 
rocket propellants, are discussed below. 

6.14.1 Analysis of the Propellants 

Each of the rocket propellants to be analyzed was 
finely divided and extracted with ether or with methyl- 
ene chloride. The extract was analzed by chromato- 
graphic-spectrophotometric procedures (see Section 
6.11). The residue from the extraction consisted prin- 
cipally of nitrocellulose but usually contained also 
inorganic substances and graphite or carbon black. 
The nitrocellulose was fractionated with 2/1 ether- 
alcohol or with methanol, and the fractions were 
analyzed for nitrogen by means of the nitrometer or 
by the Devarda procedure. The residue from the ether 
extraction was further extracted with water, and the 
resulting aqueous solution was analyzed for inorganic 
anions by polarographic procedures. Graphite and 
carbon black were estimated in the usual way, and 
metallic elements were estimated by a spectrographic 
procedure with the use of lithium as an internal 
standard; the identification of several of these in- 
organic constituents was aided by X-ray diffraction 
studies. The methods used in the examination of the 
nitrocellulose and in the identification and estimation 
of inorganic constituents have been described in Sec- 
tion 6.11. 

The gun propellants were analyzed by procedures 
similar to those mentioned above. Previously estab- 
lished procedures were used in the determinations of 
such constituents as vaseline and nitroguanidine. 

Measurements of pH were made on many of these 
powders in 1/1 acetone-water dispersions, and several 
of the rocket propellants were tested in the vacuum 
stability test at 110 C. The procedures for the vacuum 
stability tests and measurements of pH are described 
in Section 6.12. 

All the foreign rocket propellants examined were 
double-base powders, apparently prepared by solvent- 
less processes. Microscopic examination of the grains 
of typical German and Japanese propellants indi- 
cated that the grains were dry-extruded from carpet 
rolls of sheet powder. Use of the polarizing micro- 
scope indicated the presence of both positively and 
negatively birefringent fibers, an observation which 


constitutes evidence that the grains contained a blend 
of at least two nitrocelluloses differing in nitrogen 
content. 

Six German and five Japanese rocket propellants 
were examined. 

German Rocket Propellants 

21 -cm rocket 28-cm rocket-assisted shell 

15-cm high explosive rocket ATO unit 

15-cm incendiary rocket 1,000-kg jet-accelerated bomb 

Japanese Rocket Propellants 
20-cm naval rocket 20-cm army rocket 

45-cm (17.5-in.) rocket (gray grains) Suicide bomb (BAKA) 
45-cm (17.5-in.) rocket (brown grains) 

In addition, gun propellants were examined for 
the German APC 50 mm shell, A PC 88 mm shell, 
and APHY 50 mm shell; and the Japanese AT 37 
mm shell. 

The first five of the German propellants are closely 
related in composition and are markedly different 
from U. S. ballistites. They contain 30 to 35 per cent 
of DEGN as an explosive plasticizer in place of nitro- 
glycerin, which is present in amounts of 40 to 43 per 
cent in U. S. ballistites. The German powders con- 
tain as stabilizers ethylphenylurethane, diphenylure- 
thane, and acardite and contain graphite or carbon 
black as a darkening agent. The nitrocellulose in each 
is apparently a blend, one component of which is a 
high-nitrogen (about 13.0%) nitrocellulose having 
a moderate viscosity and the other a low-nitrogen 
(about 11.6%) nitrocellulose having a very low 
(^dacqueP’) viscosity. These powders show very high 
pH values in comparison to U. S. powders, and they 
contain significant amounts of magnesium or calcium; 
it appears likely that the alkaline earth metals are 
present as oxides or carbonates. The propellant from 
the xkTO unit contains about one per cent of titanium 
dioxide (rutile). 

The 1,000-kg bomb propellant differs considerably 
from the other German rocket propellants in com- 
position; it contains nitroglycerin instead of DEGN, 
contains barium sidfate but only traces of magnesium 
or calcium, and has a pH value which is considerably 
lower than the values shown by the others but is 
higher than those of U. S. ballistites. 

The Japanese rocket propellants are very different 
from the German powders in composition. They, too, 
contain blends of nitrocelluloses, but the nitrogen 
contents of the low-nitrogen components are much 
lower than in the German propellants. The Japanese 
propellants contain from 27 to 31 per cent of nitro- 
glycerin and 3 to 5 per cent of ethyl centralite. In 


(TpWiTilixTTAn 

1 


146 


PROPELLANTS 


addition, each jDropellaiit contains one additional com- 
pound as plasticizer or stabilizer : the 20-cm naval 
rocket propellant and the gray grains from the 45-cm 
rocket contain about 3 per cent of N-(o-tolyl) ure- 
thane, the BAKA propellant and the brown grains 
from the 45-cm rocket contain about 6.5 per cent of 
a-nitrophthalene, and the 20-cm army rocket pro- 
pellant contains about 4 per cent of N,N'-diphenyl- 
formamide. All the Japanese propellants except the 
brown BAKA propellant and the brown grains from 
the 45-cm rocket were gray in color and contain 
graphite or carbon black. All the propellants contain 
significant amounts of calcium, sodium, and silicious 
material ; moreover, the BAKA propellant contains 
3 to 4 per cent of potassium sulfate. The pH values 
of these propellants are intermediate between those 
of the German propellants and those of American 
ballistites. 

Curiously enough, the motors of the Japanese 45- 
cm rockets contained a random selection of gray and 
brown grains of the compositions described above. 
Consequently, traces of a-nitronaphthalene were 
found in the gray propellant. The brown grains ex- 
hibit an interesting color difference which is discussed 
in connection with the burning rate studies. 

The German gun propellants, like the rocket pro- 
pellants, contain DEGK but in smaller amounts. One 
of them, the ABC 88 mm shell propellant, contains 
in addition 32 per cent of nitroguanidine, 4 per cent 
of diphenylurethane, and 4 per cent of ethylphenylure- 
thane. The ABC 50 mm shell propellant contains 
nearly 8 per cent of ethyl centralite and more than 
1 per cent of vaseline. The 23ropellant from the 
Japanese AT 37 mm shell resembles the Japanese 
20-cm army rocket propellant hut contains a higher 
percentage of nitroglycerin, lower percentages of 
ethyl centralite and N',N-diphenylformamide, and a 
higher percentage of nitrogen in the nitrocellulose. 

The sample of Japanese AT 37 mm shell propel- 
lant consisted of only four grams of material, and 
the entire analysis, including the identification of a 
previously unknown stabilizer as N,N-diphenylforma- 
mide, was carried out with that small amount of 
material. It was largely due to the successful devel- 
opment of chromatographic techniques for powder 
analysis that the identification of the unknown com- 
pound and the estimation of the stabilizers were pos- 
sible. 

In the vacuum stability test at 110 C, the German 
propellants evolved gas at rates that were much lower 
than the rate of gas evolution of ballistite JBN, but 


the Japanese 20-cni naval rocket propellant evolved 
gas much more rapidly than JBN. It is not possible 
to interpret these results unequivocally, largely be- 
cause of the considerable differences in composition. 

6.14.2 Investigations of Linear 

Burning Rates 

Apparatus axd BpiOcedure 

An apparatus similar in many respects to that of 
CrawfoixB^^ was used for making measurements of 
linear burning rate on foreign propellants and various 
experimental powders. Its construction and the pro- 
cedure for its use have been described in detail.^^'"^ 
Since this apparatus has been very useful in obtaining 
burning rate data at high pressures with the use of 
small amounts of powder, it may be worth while to 
describe it briefly here. 

The burning rate bomb, a pressure vessel of stain- 
less steel, is equipped with a closure plug incorporat- 
ing an unsupported-area seal. The use of this seal 
obviates the need of a wrench for opening or closing 
the bomb. The powder support, which is mounted on 
the inner surface of the closure plug, carries a powder 
clamp and five pairs of binding posts. The uppermost 
pair of posts carry the ignition wire; the other four 
pairs are terminals for four fusible wires. Electric 
connections to external circuits are made through in- 
sulators in the closure plug. The bomb is connected to 
a source of nitrogen at high pressure and also to a 
tank which is used as a reservoir to increase the vol- 
ume of the system and render the conditions more 
nearly isobaric. The bomb is situated in a water bath 
for temperature control. An electronic timing circuit, 
incorporating three clocks graduated to 0.01 second, 
is used to determine the relative times at which the 
four fuse wires are burned out by the ignited powder 
strand. 

The powder is tested in the form of cylin- 

drical strands which are usually prepared from carpet- 
rolled sheet powder or from shavings of grain powder 
by extrusion through a flic in a one-inch ex- 

trusion press. The strands are cut into 18-cm lengths. 
To insure end-burning of the strands, each length is 
dipped twice in a 5% dispersion of polyvinyl alcohol 
in water; the strands are allowed to dry after each 
dipping. Four holes, spaced at 5-cm intervals, are 
drilled in each stand with a No. 78 drill, short lengths 
of V 2 -ampere fuse wire are inserted through the holes, 
and the strand is given a third dipping and allowed 
to dry. 




EXAMINATION OF FOREIGN PROPELLANTS 


147 


111 prepi^r^ition for eacli burning rate inoasnrcincnt, 
tlie strand is clamped to the powder support, the ends 
of the fuse wires are fastened to the binding posts, the 
closure plug is screwed in place, and nitrogen is ad- 
mitted to the desired pressure. After the system has 
come to thermal equilibrium, the strand is ignited at 
its upper end by electrically heating the ignition wire. 
When the flame burns out the first fuse wire the three 
electric clocks are started simultaneously and auto- 
matically. As the flame burns out the second, third, 
and fourth fuse wires the first, second, and third 
clocks, respectively, are automatically stopped. The 
three burning intervals are compared in order to 
detect any irregularities in burning, and their sum 
is used in the calculation of the linear burning rate. 

Burning rate measurements are made at pressures 
ranging from 400 to 1,900 psi and at temperatures 
ranging from 0 to 50 C. Usually the burning rate 
data obtained at each of two or three dilferent tem- 
peratures are plotted against pressure, and a smooth 
curve is drawn to represent the variation of burning 
rate with pressure at each temperature. Fi'om curves 
obtained in this way several quantities may be de- 
rived which are of considerable interest with regard 
to the suitability of the powder as a rocket propellant. 
These quantities are the pressure index (the quan- 
tity n in the equation r — where r is the linear 
burning rate at a given temperature and p is the 
pressure), the temperature coefficient of linear burn- 
ing rate at a given temperature and pressure, and 
the temperature coefficient of steady-state pressure in 
a hypothetical rocket motor at a given temperature, 
calculated for each of several representative pressures. 

Results 

The results of measurements of burning rate on 
the propellant from the German 21 -cm rocket are 
plotted in Figure 14. This propellant is unusual for 
its comparatively low burning rate (less than half 
that of JPN), and for its small dependence of burn- 
ing rate on pressure and temperature. Although the 
burning rate of this German propellant is much less 
dependent on temperature and pressure than is that 
of U. S. ballistite, the German 1,000-kg bomb pro- 
pellant gave even higher values of the pressure index 
and the temperature coefficient of steady-state pres- 
sure than were given by ballistite. 

There is an inflection at about 550 psi in the burn- 
ing rate curve for the German 21-cm rocket propellant 
at 25 C, and a more pronounced one at about 650 psi 
in the curve for 50 C. Only a weak inflection is ob- 



Figure 14. The burning rate of the propellant taken 
from a German 21-cm rocket. 


servable in the curve for 0 G. The presence of the 
inflection in the burning rate curve probably indicates 
a dilference in the burning mechanisms below and 
above the pressure corresponding to the inflection. 
A much more pronounced inflection has been observed 
in measurements of the burning rate of a sample of 
the propellant from the German 28-cm rocket-assisted 
shell. Although the phenomenon in both cases is cer- 
tainly real, it is by no means uniform; other samples 
of both the 21-cm rocket propellant and the 28-cm 
rocket-assisted shell propellant have failed to show 
these inflections. 

By far the best of the foreign ])owders studied was' 
the propellant from the Japanese 20-cm naval rocket. 
This propellant had a burning rate comparable to 
that of the German 21-cm rocket propellant, but had 
the smallest pressure and temperature coefficients of 
burning rate observed for any of the powders. 

The brown propellant from the Japanese 45-cm 
rocket also has a low burning rate and low pressure 
and temperature coefficients. This propellant exhibits 
the following very curious phenomenon. When the 
propellent grain is sectioned, it is observed that the 
material within one centimeter of the periphery and 
also the material within the same distance of the 
central perforation are brown in color and are trans- 
lucent, while the remaining material is tan in color 
and is opaque. There appears to be no difference in 
composition between the tan and brown materials; 
moreover the tan material is transformed into the 
brown material gradually on standing and more rap- 
idly when rolled at elevated temperatures. The burn- 
ing rates of both materials were measured; in order 
to obtain strands of the tan material for use in the 
burning rate studies, it was necessary to extrude chips 
cut from the grain rather than carpet-rolled sheets 


(f (iXFinKynTg 


148 


PROPELLANTS 


})ropare(l from such cliips by the usual procedure. 
At teiu})eratures below 45 C the tail material burns 
more slowly than the brown, and the brown material 
has the lower values of the temperature coefficients 
of linear burning rate and of steady-state pressure. 

Attempts to duplicate this material yielded lemon- 
yellow, translucent grains that showed no tendency 
to exist in more than one modification. Hence the 
cause of the existence of both tan and brown material , 
is completely unknown. Moreover, since the difference 
in linear burning rate between the brown and tan 
portions of the propellent grain Avould he expected 
to result in markedly regressive hurning of the grain, 
it is difficult to understand the advantage to be gained 
by the manufacture of grains having this structure, 
if indeed the existence of this structure is not acci- 
dental. The phenomenon ajipears to be general; the 
differences in color were observed in grains taken 
from two different rockets of the same type. A some- 
what similar, though less pronounced, color difference 
was observed on examination of the propellant from 
the Japanese BAIvA bomb. 

6.14.3 Preparation of Experimental 

Powders 

Because of the excellent physical properties and 
hurning characteristics of the foreign propellants, it 
was hoped that knowledge gained fi*om studying these 
projiel hints could be applied sueeessfully to the 
formulation of propellants superior to existing U. S. 
rocket propellants in physical and hurning properties. 
In order to supplement the information gained from 
analytical studies and burning rate measurements 
and to determine ways in which American propellants 
with improved properties could he made, experimental 
powders were made up in five-gram batches of rolled 
sheet and in sixty-gram batches of sheet or of dry- 
extruded gi'ain. Lommereially available materials 
were used in the preiiaration of these powders which, 
for the most jiart, were formulated on compositions 
resembling those indicated by the analyses of the 
projiellants from the German 21-cni rocket, the Jap- 
anese 20-cm naval rocket, and the Japanese 45-cm 
rocket. 

The ])owders that were prepared on compositions 
resembling that of the German 21-cm rocket propel- 
lant liad excellent physical properties, equaling or 
even surpassing those of the German propellant. How- 
ever, they did not exhibit the low pressure and tem- 
perature dependence of burning rate shown by the 
German propellant. Likewise, attempts to duplicate 


tbe excellent bui-ning ])ro[)erties of the Jajianese pro- 
])ellauts were not successful. It has already been men- 
tioned that the powders prejiared on a composition 
similar to that of the brown grains from the Japanese 
45-cni rocket did not have the peculiar structure of 
that propellant. 

It is demonstrated by these results that the chemical 
analyses of the foreign propellants did not lead to 
their conqilete characterization. The results of some 
experiments described elsewhere indicate that the 
constituents responsible for the excellent burning prop- 
erties of the foreign propellants reside mainly in 
their ether-insoluhle parts. These eonstituents may 
he the nitroeellnlose blends, or their components, to 
which desirable characteristics may have been im- 
parted by techniques unknown in this country. Cer- 
tainly the procedures now available for the examina- 
tion of the nitrocellulose in a jiowder do not provide 
a characterization nearly complete enough to permit 
the duplication of the nitrocellulose in all of its prop- 
erties. Hence, with the analytical techniques now at 
hand, the practical limit of usefulness of the kind of 
exiieriments described above has been approached, 
and it appears that further information can be gained 
only by means of experiments along new lines. 

The capitulation of Germany and the consequent 
revelation of German technical secrets has afforded 
opportunities, much greater than those afforded by 
the capture of isolated enemy propellants, for the 
formulation of improved propellants for IT. S. rock- 
ets. The techniques for the preparation and testing 
of small batches of experimental double-base powder 
might be expected to find ready application in studies 
of rocket propellent compositions discovered by Allied 
investigators in Germany as a result of their inter- 
rogation of German technical personnel. Indeed, these 
techniques have been successfully applied to a study 
of the “Einheits Bulver’^ rocket propellent composi- 
tion, a standard composition intended for universal 
jirodnction in ({ermany during the last year or two 
of the war in Europe. The experiments made on the 
Einheits composition were the most fruitful of any 
of the experiments made on foreign rocket jiropellent 
compositions at the California Institute of Tech- 
nology. 

The Einheits composition resembles the composi- 
tion of the German 21-cm rocket propellant in many 
respects, but it contains, in addition to the com- 
pounds positively identified in the analysis of the 
21-cm rocket propellant, the following constituents: 
0.2^ magnesium oxide, 0.6^ potassium nitrate, and 


frT7\|-|iip:\-|i.Ml 


MISCELLANEOUS 


149 


1.5^ liydrocelluloso. Moreover it eonttiins xVcardite 
11 (N,N-diplieiiyl-N'-methyliirea) in i)lace of Acar- 
dite 1 (acardite, X,N-diplienylurea) . Experimental 
powders prepared at the California Institute of Tech- 
nology on compositions resembling the Einheits com- 
position equaled or surpassed in burning character- 
istics all the foreign propellants studied in that lab- 
oratory. The experiments indicated that the presence 
of hydrocellulose, potassium nitrate, and magnesium 
oxide together was the factor chiefly responsible for 
the extraordinarily low temperature and pressure de- 
pendence of burning rate of the Einheits-type pow- 
ders. 

It does not follow, however, from consideration of 
the excellent burning characteristics of the German 
21-cm rocket propellant that this propellant must 
contain hydrocellulose and potassium nitrate. It does 
not seem very likely that both these substances could 
have escaped detection if they were present in the 
propellant. 

Some further experiments have indicated that the 
inclusion of potassium nitrate, hydrocellulose, and 
magnesium oxide in certain powders of low potential 
(such as modifled German-type powders, Japanese- 
type powders, and H-4 powders) significantly lowers 
the dependence of burning rate on temperature and 
pressure. Xo beneficial effects have been obtained from 
experiments in which these three materials wei’e in- 
corporated in high-potential hallistite such as JPH. 

The experiments described above give considerable 
promise of pointing the way toward the formulation 
of improved rocket-propellent compositions. If these 
experiments are continued and extended, an under- 
standing of the nature of the effects of hydrocellulose, 
potassium nitrate, and magnesium oxide may per- 
haps be gained, with the possible result that other 
and better methods may be found for improving the 
burning characteristics of rocket-propellent powders. 

6.15 MISCELLANEOUS 

A variety of miscellaneous activities of Division 8 
having to do more or less directly with propellants 
can be mentioned briefly in this section. 

Two studies have been made of the thermochemical 
properties of propellants. The first^^^ presents data on 
both commercial and experimental compositions; the 
second^^® presents data on Albaniteand related powders, 
on Cordite N, and on a number of EDX propellants. 
Since it was found that in some compositions the 


calculated values for the heat of explosion (obtained 
from tlie summation of the heat values of the indi- 
vidual ingredients) difl'ered ap})reciahly from the ob- 
served values, it was recommended that calorimetric 
measurements he made a i)art of any future research 
program on propellants. 

The partial l)urning of propellants and of nitro- 
cellulose has also been studied. An apparatus, con- 
sisting essentially of a high-pressure bomb fitted with 
a bursting diaphragm, was developed for this pur- 
pose. Ifliotographs of grains partially burned in the 
bomb illustrate flaws in propellants. The apparatus 
should be of use both in the study of experimental 
compositions and as a control of quality in the produc- 
tion of propellent grains.-^^’’^^^ 

Work on the partial burning of nitrocellulose be- 
gan with the observations made at the Ballistic Re- 
search Ijaboratory, Aberdeen Proving Ground, that 
nitrocellulose when decomposed under reduced pres- 
sure yields a red substance (RS) and a tvhite sub- 
stance (WS). Division 8 was asked to determine the 
composition of these products, which it was thought 
might he of significance in an understanding of the 
mechanism of burning of nitrocellulose. 

The red substance is a liquid obtained when nitro- 
cellulose undergoes thermal decomposition at about 
100 mm pressure. The yield of RS amounts to 35 to 
40^ of the weight of the nitrocellulose decomposed. 
RS has been analyzed for formaldehyde, glyoxal, formic 
acid, water, acetic acid, ethyl acetate, nitrous acid, 
and nitric acid. These constituents account for 80 to 
00 by weight of the RS. Glyoxal, formaldehyde, 
formic acid, and water are considered to be the signfi- 
cant decomposition products. The first two are ])res- 
ent in approximately equimolar amounts; signifi- 
cantly smaller molar amounts of formaldehyde and 
significantly larger molar amounts of water are present. 

The white substance is an amorphous powdery solid, 
obtained when nitrocellulose undergoes thermal de- 
(‘om])osition at pressures below 10 mm. The yield of 
WS amounts to 05 to 70^ of the weight of nitro- 
cellulose decomposed. AYS is apparently a complex 
mixture. It gives a positive iodoform test, positive 
aldehyde tests, and liberates iodine from potassium 
iodide. WS decomposes more or less rapidly in solu- 
tion; no solul)le decomposition products have been 
isolated, but carbon monoxide, nitrous oxide, and 
nitrogen have been identified among the gaseous prod- 
ucts. On heating crude AA^S with hydrochloric acid, 
carbon dioxide, furfural, nitrous and nitric acids are 
formed. 


150 


PROPELLANTS 


Furtlier work with crude WS showed that it could 
be purified by solution in methanol and precipitation 
with ether, followed by washing with water. The yield 
in this purification is 40^. The nature of the material 
lost in the purification is not known. The purified 
white substance (PWS), on the basis of analytical 
data and chemical reactions, is a mixture of closely 
related substances of very similar degrees of polymeri- 
zation — average molecular weight about 1,500 — with 
similar hut not identical distributions of substitu- 
ents.^^® 

AVork on the decomposition of cellulose nitrate 
under reduced pressure was transferred from Division 
8 to the Ordnance Department on February 28, 1945. 

Although Division 8, other than through its con- 
tract at the California Institute of Technology, did 
not devote much time to work Avith conventional 
double-base poAvders, some Avork on these poAvders Avas 
done at the Explosives Research Laboratory. 

At the request of Division 3, Section H, a solvent- 
less cordite extrusion press A\^as set up at the Explo- 
sives Eesearch Laboratory of Division 8 at Bruceton, 
I^eimsylvania. The press Avas used for the extrusion of 
propellent grains desired by the groups AA^orking on 
rockets, and a study Avas made of the factors affecting 
successful extrusion. Essentially, this press Avas 
a service unit for the groups Av^orking on rockets at a 
time Avhen it was difficult to secure soh^ntless cordite 
grains for use in rockets. After these grains became 
available elseAvhere, the apparatus Avas used for press- 
ing experimental 8.5-in. diameter grains of composite 
propellant (Section 6.2). 

A study of methods of inhibiting the burning of 
double-base propellants by the use of restrictive coat- 
ings has shoAvn that copper- or silver-plated coatings 
are unsatisfactory because they separate from the grain 
on temperature cycling. The use of cellulose coatings 
Avas more promising, hut the Avork Avith this material 
Avas not taken beyond a preliminary stage. 

Because the separation of nitroglycerin from double- 
base poAvders represents a })otential hazard, a survey 
of the literature on this subject Avas prepared and an 
experimental study of the problem Avas outlined and 
started. The termination of the work of Division 8 


took place before this experimental program Avas com- 
pleted. The principal conclusion from the Avork Avas 
that there is little danger of the separation of nitro- 
glycerin from modern double-base poAvders at Ioav 
temperature.®®^’^^® 

A completely dift'erent problem Avas that of develop- 
ing a chemical igniter system for jet-propulsion de- 
vices employing fuming nitric acid-gasoline as fuel. 
Examination of a variety of materials led to the selec- 
tion of a turpentine solution containing 30% by vol- 
ume of du Pont SDO (a divinylacetylene polymer), 
inhibited Avith 1% of 2,6-di-^-butyl-4-methylphenol, 
as the initiator of choice. The operating procedure is 
to introduce the nitric acid and initiator into the motor, 
then to introduce the gasoline, and stop the floAV of 
initiator. Operating and egnineering details are given 
in the original reports.^^®*^^’’ 

Considerable synthetic organic chemical AVork Avas 
done at the California Institute of Technology Avhere 
it Avas necessary to prepare small amounts of a num- 
ber of compounds in connection Avith the research pro- 
gram on propellants.^^® The following neAv compounds 
Avere synthesized : 


N,N-Diphenyl-N '-ethylurea 
N , N '-Diethy l-N-phenylurea 
N-Phenyl-N,N',N'-triethyl- 
urea 

2-Ni tro-N-ethylcarbanily 1 
chloride 

2-Nitrocentralite 

4-Nitro-N-ethylcarbaiiilyl 

chloride 


4-Nitro-N-ethylcarbanilide 
4-Nitro-N '-ethylcarbanilide 
2,4,4^"Trinitrocentralite 
4-Nitro-N -ethyl-N -phenyl- 
benzamide 

4- Amino-N-ethyl-N -])heny l- 
benzamide 

4-(N-Ethylamino)-N-ethyl-N- 

phenylbenzamide 


The folloAving compounds had been prepared pre- 
viously. NeAver improved syntheses have been devised 
for them or iieAv and interesting properties have been 
observed. 


N,N-Diphenylcarbamic 

anhydride 

N -Ethyl-N '-phenylurea 
N-Ethyl-N,N',N'- 
triphenylurea 
4-Ni trocentrali te 
Phthalide 
4-Nitrocatechol 
1 ,3-Diphenyl-3-ethyltriazene 


4-(N-Ethylamino)-azobenzene 

N-Nitroso-4-nitrodiphenyla- 

mine 

N-Nitrosodinitrodiphenyla- 

mine 

2,2',4-Trinitrodiphenylamine 
Tetrapheiiylhydrazine 
N - (o-T olyl)-urethane 
Phosgene-triethylamine 
complex 


Attempts to inhibit the 32-degree transition of am- 
monium nitrate Avere not successful.^^® 




Chapter 7 


TRACERS AND IGNITERS^ 


R KSKAJiC’ii ON TKACEKs b}' Divisioii 8 was begun in 
June 1943 under Project XO-151 at the Explo- 
sives Pesearcli Laboratory [ERL]. A ery little atten- 
tion was paid in this work to the possibility of using 
tracer systems otlier than strontium nitrate-mag- 
nesium. The emphasis in the work was on methods of 
incor})orating and loading this particular mixture 
and on attempts to determine the factors responsible 
for the behavior of tracers. 

Pecause of the extensive ex])erience with thermo- 
})lastic resinous binders in the preparation of molded 
composite proi)ellants (see Section 3.2), particular 
attention Avas given to the use of these binders in mak- 
ing up tracers. It Avas found that by incorporating 
these resinous binders in edge-runner mills, tracer 
com})ositions Avith good molding properties could be 
obtained. IIoAvever, these compositions functioned 
}>oorly Avhen they Avere loaded at pressures beloAV 
50,000 psi. The conventional Avax binders, it Avas also 
shoAvn, corrld be incorporated in edge-runner mills, 
but adequate test data on the compositions prepared 
in this Avay are not available. 

As shoAvn by experiem-e elscAvliere, a layer of Avax 
betAveen the tracer com])osilion and tbe shell markedly 
improves tracer i)erl'ormance. Similarly, the incoiqm- 
ration of organic fuels into the tracer mixture re- 
sulted in better performance. The number of bloAV- 
outs Avas reduced, the color of the '^tracer Avas inten- 
sified, and the burning time Avas increased. 

One of the great needs in tracer research is the 
development of static tests Avhich can be carried out 
in the laboratory and Avhose results can be correlated 
Avith tracer performance. A start in this direction Avas 
made at the Exjdosives licsearch Laboratory by the 
construction of a bomb Avhich i)crmittcd static firing 
of tracers so that ignitability, bloAvouts, and otber 
jihenomena could be studied. The results obtained Avith 
the bomb could not be correlated exactly Avith the re- 
sults of gun tests, but the results Avith the bomb 
proved very useful. 

During the course of the AV'ork on tracers at ETIL a 
number of miscellaneous observations Avere made about 
tracer behavior. These observations, together Avith the 

®This chapter is based on a summary prepared by 8. II. 
.\spinall. 


speculations to Avhich they led, and the experimental 
AA'ork described in the preceding paragraphs are re- 
ported in reference 1. 

A much more far-reaching and comprehensiAe pro- 
gram on tracers AA^as initiated under Projects NO-151 
and OD-159 at the Metal and Thermit Corporation 
in November 1943. As a preliminary to the experi- 
mental Avork a revieAv of U. S., British, and Canadian 
Avork on tracers Avas prepared.^ All the exjierimental 
Avork done by the Metal and Thermit ( Vi'poration, to- 
gether Avith the conclusions draAvn from that AA'ork have 
been given in detail in a report AAdiich should be ex- 
amined carefully by anyone interested in the subject.^ 
Because of the varied nature of the investigations and 
the number of anomalies and complications Avhich Avere 
encountered, it is feasible only to mention briefly a fcAV 
of the items Avhich Avere considered in the study and 
described in the report. 

A revicAv is presented of all the factors Avhich influ- 
ence the ignitahility of an igniter and of the static 
tests used to measure this property. Tavo types of tests 
to measui’e ignitability have been evaluated experi- 
mentally, but it has been concluded that neither one 
gave adequate correlation Avith ])erformance in a gun. 
Burning characteristics and heats of reaedion of igniter 
compositions have been determined, and consideration 
has been given to the relation of these and other fac- 
tors to the burning time of an igniter and its ability 
to transfer burning to the tracer composition. 

Because of the poor storage characteristics of tracer 
ammunition under conditions of high temperature 
and humidity, attention Avas given to all the factors 
.influencing the stability of igniters. Although there 
arc many factors Avhich influence the useful life of an 
igniter composition, all the experimental Avork of the 
conti-actor AA'as devoted to the improvement of the 
chemical stability of the mixture itself. It Avas dem- 
onstrated in the laboratory that it should be possible 
to improve greatly the storage life of tracer ammuni- 
tion containing standard bright igniters by employing 
either, or preferably both, of the folloAving modifica- 
tions. 

1. The corrosion resistance of the magnesium can 
be increa.sed by treating the surface Avith a dichromate 
Avash or Avith an organic dye. Ea^cii better stability is 


fWFIDENTTATj 


151 


152 


TRACERS AND IGNITERS 


obtained by replacing inagnesinin with a surface 
treated niagnesiiiin-aluniinum alloy. 

2 . The asphaltnm binder, which actually accelerates 
the deconi})osition of the metal and peroxide, should 
be replaced with calcium resinate or some other binder 
which exerts a strong protective elfect. 

There is less standardization and less experience 
with dark or dim igniters, but certain tentative con- 
clusions have been drawn which should lead to en- 
hanced stability of such igniters. 

For a variety of operational reasons, there have been 
established from time to time a number of require- 
ments for tracer amniuiution having a dim igniter. 
A detailed study was made of compositions which 
function as dim igniters, with primary emphasis on 
obtaining a mixture having a burning distance of 400 
yards in the Mark 11 40 mm tracer. On the basis of 
preliminary gnu trials, it was concluded that a mix- 
ture of manganese-barinm peroxide binder shows con- 
siderable 2)romise as a dim igniter. 

A similar study of tracer compositions has heen 
made. The question of tracer visibility is extremely 
complex, involving, among other things, psychological 
factors which are difficult to evaluate, but some in- 
formation has been obtained on this subject. Cdiemical 
instability of tracer compositions leads to serious tracer 
malfunction, but the problem is less severe than with 
igniter compositions because the tracer compositions 
are inherently more stable and arc protected from 


moistiue by the igniter composition. However, im- 
provements can be made by modihcation of the metal 
and binder (for the same reasons as indicated for ig- 
niters), and the hygroscopicity of specification grade 
strontium nitrate may be sharply reduced by a water 
wash. The effects of composition, physical state, load- 
ing technique, and tracer cavity tiiniensions on con- 
solidation have been discussed. 

By use of the Explosives Besearch Laboratory bomb 
mentioned above, an extensive laboratory study Avas 
made of bloAA'outs and prematures. These very coni- 
l)lex phenomena are not Avell understood in spite of 
the large amount of information obtained during 
this work and by previous investigators. 

An entirely different aspect of the Avork in this 
held Avas the development of methods for the identi- 
fication and analysis of primer compositions. These 
methods had to be rapid in their application and they 
liad to be applicable to quite small amounts of mate- 
rial. Tavo procedures Avere developed. Folarographic 
analysis permitted the quantitative analysis of 100- 
mg samples of primer mixtures for antimonous sulhde, 
cuprous thiocyanate, lead azide, mercuric fulminate, 
and potassium chlorate.^ 

A qualitative analysis for 20 primer constituents 
Avas developed Avhich Avas based on the optical and crys- 
tallographic constants of the individual compounds 
and in their behavior with selected chemical reagents. 
Reference data and procedures are given in the 
original report.^ 


(Tnxi 


GLOSSARY 


Acardite. l^iisyniin. dii)henylurea. 

Al. Aliinnmiin. 

Alumatol. an /TNT/Al. 

Amatex. RDX/TNT/Al. 

Amatol. AN/TXT. 

AX. Aniinoniiim nitrate. 
Axhydroenneaheptitol Pentanitrate. 


CHs— C(CH20X02)2 

I I 

0 CHOXO 2 

1 I 

CH 2 — C(CH20X02)2 


ASC Bomb. Antisiibinarine shaped-charge bomb. 

ASCFT Bomb. Antisubmarine shaped-charge follow through 
bomb. 

ATO. Assisted take-off. 

Baronal. Ba(XO3)2/TNT/Al-50/35/15. 

Beaxo. a spherical hand grenade. 

BSX. XO 2 XO 2 XO 2 


ERL. Explosives Research Laboratory, the central labora- 
tory of Division 8, located at Bruceton, Pa. 

Explosive D. Ammonium picrate. 

Fivonite. Tetramethylolcyclopentanone tetranitrate. 

FXH. Flashless nonhygroscopic. 

Fume-off. The oxidative destruction of byproducts in nitra- 
tion reactions. 

H-4 PoAVDER. A ballistite tyjie rocket powder (58% nitrocel- 
lulose, 30% nitroglycerin, 2,5% dinitrotoluene, 8% ethyl 
centralite, and 1.5% potassium sulfate) Avhich is cooler and 
slower burning than JPX or JPT. 

Haleite. Ethylenedinitramine. 

HBX. Torpex containing 5% of D-2. 

H.E.A.T. High explosive anti-tank. 


Heptryl. 


O 2 X 



X ()2 

^ X ()2 

/ 

— X C(CH20N02)3 


CH 3 C 02 CH 2 X— CH 2 X— CH 2 X— CH 20 COCH 3 
ButyIXEXA. C4H9X(X02)CH2CH20X02 
Cast Double-Base Powder. 

Type O. Castings made from grains of double-base powder 
to which nitroghxerin and a non-volatile solvent have 
been added. 

Tyi)e 1. Like ty])e O, but containing rate control strands 
of solvent-extruded com])osite pro]iellant. 

Type 11. Like type O, but containing uniformly distributed 
rate control grains. 

Composition A. A desensitized RDX having the usual com- 
position RDX/ wax-9 1/9. 

Composition B. 60/40/1 — RDX/TXT/wax. 

Composition C. The American name for PE-2. 
Composition C-2; Composition C-3. American PE's con- 
sisting of RDX plasticized Avith nitrotoluenes and thick- 
ened Avith nitrocellulose. 

Cordite X. A flashless double-base i)roi)ellant containing 
about 55% of nitroguanidine. 

CyclohexyIXEXA. C6HiiX(X02)CH2CH20X02. 
Cyclonite. See RDX. 

Cyclotol. a castable mixture of RDX and TXT, e.g., 
65/35 Cyclotol Avhich is RDX/TXT-65/35. 

D-1. A desensitizer for high explosives. The composition is 
paraffin/nitrocellulose /lecithin-84/14/2. 

D-2. A modification of D-1 in Avhich a higher-melting paraf- 
fin is used. 

DDP. DIXA/Dibutyl phthalate/centralite-85. 5/10/1. 5. 
DEGX". Diethylene glycol dinitrate. 

Dentex. RDX/DXT/Al-48/34/18. 

DIXA. 6f5(/3-Xitroxyethyl)nitramine. 

DiPEHX. Dipentaerythritol hexanitrate. 

DXP. 2,4-Dinitrophenol. 

CH 2 — X CH 2 

I I I 

DPT. O 2 X N CH 2 X X()2 

I I I 

CH 2 — X CH 2 

EDNA. See Haleite. 

Ednatol. a mixture of Haleite and TNT. 


XO 2 

He xamine. Hexamethylenetetramine. 

Hexanite. Hexanitrodiphenylamine. 

Hexogen. See RDX. 

HMX. Cyclotetramethylenetetranitramine, a high explosive 
obtained by the nitrolj'sis of hexamine in the presence of 
acetic anhydride. 

HVAR. High-velocity aircraft rocket. 

JP (also JPH, JPX, JPT, JP 204). This abbreviation, fol- 
lowed by another letter or by a number, e.g. JPH, JPX, 
JPT, JP 204, refers to ballistic type rocket poAvders. JPT, 
for example, has the composition: 59% nitrocellulose 
(13.25% nitrogen), 40% nitroglycerin, and 1% ethyl cen- 
tralite, to Avhich are added 0.2% of diphenylamine and 
0.1% of nigrosine dye. 

IMethyIXEXO. CH3X(X02)CH2CH20X02. 

Minol. TXT/AX/Al. A typical composition is 40/40/20. 

MXO. C0X(X02)CH3 

I 

C0X(X02)CH3 

XEXA. )8-Xitroxyethylnitramine O 2 XOCH 2 CH 2 XHXO 2 . 

XEXO. C0X(X02)CH2CH20N02 

I 

C0X(X02)CH2CH20X02 

NIP. Xitroindene polymer. 

OxYNiTRATiON. The direct conversion of benzene to dini- 
trophenol or picric acid. 

PA. Picric acid. 

PEI. Penetaerythritol C(CH20H)4. The same abbreviation 
is also used for plastic explosive. 

PEl-l. A British plastic explosive of the composition RDX/ 
PE oil — 88/12. The PE oil (plastic explosive oil) consists 
of 10% of crepe rubber in a 2:1 vaseline/paraffin oil base. 

PE-2. A British plastic explosive of the composition 88/12- 
RDX/PE oil. The PE oil consists of vaseline/paraffin oil/ 
lecithin — 1 10 /55 / 10. 

Pentolite. a castable mixture of PETX and TXT. The 
most generally used composition is 50/50. 

Pentonal. PETX/TNT/Al 47/33/20. 


“This glossary includes only those terms and abbreviations which are not in the standard books on explosives and which 
are not defined in the text of the Summary Technical Report. 


IlioximKXTTTITJ 


153 


154 


GLOSSARY 


l’EP-2. A ])lastic explosive of the composition PETN/Gulf 
Crown Oil E-85/15. 

PEP-3. Like PEP-2, but having the composition PETN/ 
Gulf Crown Oil E-86/14. 

PETN. Pentaerythritol tetranitrate. 

PiCRATOL. A mixture of PA and TNT. 

PIPE. An insensitive plastic explosive of the composition 
PETN/Gulf Crown Oil E-81/19. 

PNL. See D-1. 

Pressure Exponent. The exponent n in the formula, R = 
6p”, which describes the pressure dependence of the burn- 
ing rate of a propellant. 

PTX-1. RDX/tetryl/TNT. A typical composition is 30/ 
50/20. 

PTX-2. PETN/RDX/TNT. 25/44/28. 

RDX. Cyclotrimethylenetrinitramine, a high explosive ob- 
tained by the nitrolysis of hexamine. 

RDX(B). The mixture of RDX and HMX obtained by the 
combination process. 

RDX Polar PE. A plastic explosive for use at low tempera- 


tures. The comi)osition is RDX/oil= 88/12. The oil is a 95/5 
mixture of Gulf .300 Process Oil and lecithin. 

RIPE. An insensitive plastic explosive of the composition 
RDX/Gulf Crown Oil E-85/15. 

RPL. Radford Pilot Lot, from Radford Ordnance Plant. 

ScHNEiDERiTE. Dinitronaphthalene (mixture) /AN-87/13. 

SixoLiTE. Tetramethylolcyclohexanol pentanitrate. 

Specific Impulse. The thrust in pound-seconds per pound 
of propellant delivered by a rocket propellant. 

Temperature Coefficient of Propellants. The change 
in the pressure, thrust, and burning time of a propellant 
with change in initial temperature. 

Tetrytol. Tetryl/TNT. 

TNB. 1,3,5-Trinitrobenzene. 

TNEB. 2,4,6-Trinitro- 1-ethylbenzene. 

Torpex-2. RDX/TNT/Al-42/40/18. 

Trimonite . 1-Nitronaphthalene / P A- 1 2 /88. 

Tritonal. TNT/aluminum mixtures; e.g. 80/20 Tritonal 
is TNTA\l-80/20. 

UE. Underwater Exi)losive. A synonym for Tritonal. 




BIBLIOGRAPHY 


Numbers such as Div. 8-101-Ml indicate that the document listed has been microfilmed and that its title appears in 
the microfilm index printed in a separate volume. For access to the index volume and to the microfilm, consult the Army 
or Navy agency listed on the reverse of the half-title page. 


T he following brief description of the system used 
by Division 8 for reporting the results of its work 
should be of assistance to those users of this Sum- 
mary Technical Report who have occasion to go be- 
yond the summary to the original reports. 

Division 8 has issued two types of reports : Interim 
Reports and OSRD Reports. Interim Reports were 
issued approximately monthly. Their purpose was to 
make available as quickly as possible to interested 
and qualified persons in the United States and the 
British Empire the results of investigations under 
way in the Division. Every contractor was required 
to submit a monthly report on his work; all the re- 
ports in each field of work formed the monthly In- 
terim Report in that field. The information in the 


Interim Reports is tentative and subject to revision. 
The OSRD reports are also based on contractors^ re- 
ports; but each OSRD Report deals, almost without 
exception, with the work of a single contractor. Each 
contractor was required to submit a report on his 
work, either at six-month intervals or on completion 
of a unit of the assignment; the OSRD report is 
constructed from the contractor’s report. 

The list which follows gives the various series of 
Interim Reports issued by Division 8. The letters 
preceding each series form the abbreviation used in 
referring to the series in the Technical Summary. 
Thus, the reference SC-1, Aug. 15 to Sept. 15, 1943, 
refers to the first issue of the Division 8 Interim Re- 
ports on shaped charges. 


INTERIM REPORTS 


CF Controlled Fragmentation and Shaped Charges, Numbers 
1, Aug. 15 to Sept. 15, 1942, through 13, July 15 to 
Aug. 15, 1943. 

DFA Detonation, Fragmentation, and Air Blast, Numbers 1, 
Aug. 15 to Sept. 15, 1943, through 20, July 15 to Aug. 
15, 1945. 

FS Fundamental Study of Explosives, Numbers 1, Aug. 15, 
to Sept. 15, 1942, through 13, July 15 to Aug. 15, 1943. 

JP Propellants for Special Jet Propulsion Devices, Numbers 
1, Aug. 15, to Sept. 15, 1944, through 12, July 15 to 
Aug. 15, 1945. 

MK 29 Mark 29 Device, Numbers 1, Nov. 15 to Dec. 15, 1942, 
through 9, Sept. 15 to Oct. 15, 1943. 

ODP Organic Development Problems, Numbers 1, Nov. 15 to 
Dec. 15, 1942, through 27, Jan. 15 to Feb. 15, 1945. 

PT Preparation and Testing of Explosives, Numbers 1, 


Aug. 15, to Sept. 15, 1942, through 36, July 15 to 
Aug. 15, 1945. 

RP Rocket Propellants, Numbers 1, Aug. 15 to Sept. 15, 
1942, through 36, July 15 to Aug. 15, 1945. 

RRC RDX and Related Compounds, Numbers 1, Dec. 15, 
1942 to Jan. 15, 1943, through 22, Sept. 15 to Oct. 15, 
1944. 

SC Shaped Charges, Numbers 1, Aug. 15 to Sept. 15, 1943, 
through 24, July 15 to Aug. 15, 1945. 

SP Special Propellants, Numbers 1, Aug. 15 to Sept. 15. 

1942, through 35, July 15 to Aug. 15, 1945. 

TC Tracer Compositions, Numbers 1, May 15 to June 15, 

1943, through 18, July 15 to Aug. 15, 1945. 

UE Underwater Explosives and Explosions, Numbers 1, 
Aug. 15 to Sept. 15, 1942, through 21, Apr. 15 to May 
15, 1944. Beginning with Number 22 this series of 
reports was issued by Division 2. 


As a guide to the OSRD reports, the reader is re- 
ferred to OSRD 6630, the last report issued by 
Division 8. The report gives, for every report issued 
by the Division, the following information: the 
OSRD number and, for the very early reports, the 
former Division B serial number; the title; the name 
of the author or authors; the month and year of 
issue; the number of pages, illustrations, and tables; 


the pertinent Army and Navy project numbers; and 
an abstract. There is also a subject index. 

Finally, attention should be called to two reports 
of general interest; OSRD 5401, which is an intro- 
duction to both the theoretical and the practical as- 
pects of explosives and explosions; and OSRD 2014, 
which is a compilation of data on the properties of 
explosives. 


I llTHiMI 


155 


156 


BIBLIOGRAPHY 


Chapter 1 

1. The Preparation of Cyclonite, Werner E. Bachmann, Frank 

C. Whitmore, and Walter R. Kirner, OSRD 65, Serial 2, 
Jan. 17, 1941. Div. 8-101-Ml 

2. The Preparation of Cyclonite, RDX, Detailed Report on the 

Nitration of Hexamethylenetetramine, Frank C. Whitmore, 
OSRD 100, NDCrc-8 and NDCrc-66, Service Project 
OD-12, Serial 38, to June 1, 1941, Pennsylvania State 
College, June 11, 1941. Div. 8-101-M2 

3. The Preparation of RDX by the Direct Nitrolysis of Hexam- 
ine, Marvin Carmack, OSRD 5398, OEMsr-646, Service 
Project OD-12, University of Pennsylvania, Aug. 7, 1945. 

Div. 8-101-M14 

4. The Preparation of Cyclonite, RDX, Werner E. Bach- 

mann, OSRD 150, NDCrc-87, Service Project OD-12, 
Final Report 88, to Sept. 15, 1941, University of Michigan, 
Oct. 8, 1941. Div. 8-101-M4 

5. The Preparation of RDX, John R. Johnson, OSRD 159, 
NDCrc-23, Service Project OD-12, Report 97, to Sept. 15, 

1941, Cornell University, Oct. 27, 1941. Div. 8-101-M5 

6. Studies Relating to the Ross Process, John R. Johnson, 

OSRD 979, OEMsr-193, Serial 406, Cornell University, 
July 30, 1942. Div. 8-101.2-Ml 

7. Studies on the Preparation and Properties of RDX, Werner 

E. Bachmann, OSRD 820, NDCrc-87, Service Project 
OD-12, Report 328, to August 15, 1942, University of 
jMichigan, Aug. 24, 1942. Div. 8-101-M8 

8. Studies Relating to the Bachmann Process, John R. Johnson, 
OSRD 800, OEMsr-193, Service Project OD-12, Report 
318, to July 30, 1942, Cornell University, Aug. 12’ 1942. 

Div. 8-101-M7 

9. Nitration of Mixtures of Ammonium Acetate and H examine, 
Frank C. Whitmore, OSRD 540, NDCrc-66, Report 234, 
to April 17, 1942, Pennsylvania State College, Apr. 30, 

1942. Div. 8-105-M4 

10. Crystallographic Studies of RDX, HMX and Related Com- 

pounds, John R. John.son, OSRD 694, OEMsr-193, Service 
Project OD-12, Report 289, to June 30, 1942, Cornell 
University, July 15, 1942. Div. 8-110.3-M2 

11. The Polymorphism of HMX, Alfred T. Blomquist, 
Report to January 30, 1943, OSRD 1227, OEMsr-193, 
Service Project OD-12, Cornell University, Feb. 27, 1943. 

Div. 8-102-M2 

12. Crystallographic Studies of Compounds Related to RDX and 
HMX, Alfred T. Blomquist, OSRD 1803, OEMsr-193, 
Service Project OD-12, Progress Report to Aug. 31, 1943, 
Cornell University, Sept. 16, 1943. Div. 8-110.3-M4 

13. The Sensitivity of RDX, HMX and RDX- HMX Mixtures, 
John R. Johnson, OSRD 797, Service Project OD-PJ, Re- 
port 317, to July 30, 1942, Aug. 12, 1942. Div. 8-202-IVI2 

14. The Impact Sensitivity of HMX and of RDX-HMX Mix- 

tures, Werner E. Bachmann, Alfred T. Blomquist, L. G. 
Davy and Frank C. Whitmore, OSRD 4099, OEMsr-245, 
Service Project OD-12, University of Michigan, Sept. 5, 
1944. Div. 8-102-M4 

15. The Mechanism of Formation of Cyclonite, George B. Kis- 
tiakowfsky, and G. P. Baxter, OSRD 950, OEMsr-342, 
Service Project OD-12, Report 393, to Oct. 1, 1942, 
Harvard University, Oct. 14, 1942. Div. 8-101-M9 

16. The M echanism of Formation oj Cyclonite, Marvin Carmack, 

OSRD 1733, OEMsr-646, Service Project OD-12, Progress 
Report to July 1, 1943, University of Pennsylvania, 
Aug. 21, 1943. Div. 8-101-M13 

17. Studies on RDX (B) and Related Compounds, Werner E. 

Bachmann, OSRD 5186, OEMsr-245, Service Project 
OD-12, Report to Feb. 28, 1945, University of Michigan, 
June 9, 1945. Div. 8-101.2-M5 


18. Studies on the Mechanism of Formation of Cyclonite, RDX, 
Marvin Carmack, Isaiah Von, J. J. Leavitt, and Frederick 
A. Kuehl, Jr., OSRD 6628, OEMsr-646, Service Project 
OD-12, University of Pennsylvania, Mar. 1, 1946. 

Div. 8-101-M16 

19. The Preparation of HMX, Werner E. Bachmann, OSRD 
1981, OEMsr-245, Service Project OD-12, Report to Oct. 

I, 1943, University of Michigan, Nov. 3, 1943. 

Div. 8-102-M3 

20. Preparation of HMX, Frank C. Whitmore, OSRD 652, 
OEMsr-243, Service Project OD-12, Report 274, to June 
22, 1942, Pennsylvania State College, June 23, 1942. 

Div. 8-102-Ml 

21. Engineering Laboratory Investigation of Cyclonite Process, 
OSRD 612, OEMsr-181, Service Project OD-12, Serial 257, 
Western Cartridge Com])any, June 8, 1942. 

Div. 8-101-IM6 

22. Investigation of the RDX (B) Process, OSRD 1044, OEMsr- 

220, Service Project OD-12, Final Report 431, to Oct. 12, 
1942, E. 1. duPont de Nemours and Company, Inc., 
Nov. 21, 1942. Div. 8-101. 1-Ml 

23. RDX Experimentation, Vols. I and II, OSRD 958, OEMsr- 

393 and OEMsr-397, Service Projects OD-12 and OD-04, 
Formal Report 412, covering period from Jan. 21 to 
Aug. 8, 1942, Tennessee Eastman Corporation, Oct. 30, 
1942. Div. 8-lOl-MlO 

24. A Study of Recovery of Acetic Acid and Ammoniu7n Nitrate 
from the Bachmann Process, Frank C. Whitmore, OSRD 
393, NDCrc-8, Service Project OD-12, Progress Report 
182, to Feb. 1, 1942, Pennsylvania State College, Feb. 17, 

1942. Div. 8-110.4-M2 

25. Investigation of the Melting Point of RDX, Frank C. Whit- 

more, OSRD 538, OEMsr-243, Service Project OD-12, 
Report 233, to April 20, 1942, Pennsylvania State College, 
Apr. 30, 1942. Div. 8-203-Ml 

26. The Potentiometric Titration of Filtrates from the Bachmann 
Process, Frank C. Whitmore, OSRD 654, OEMsr-243, 
Service Project OD-12, Rejwrt 276, to June 22, 1942, 
Pennsylvania State College, June 23, 1942. 

Div. 8-110.4-M4 

27. Specific Conductance Measuremeids of Ammonium Ni- 
trate-Nitric Acid, Water Mixtures, Frank C. Whitmore, and 

J. C. Aston, OSRD 1195, OPlMsr-243, Service Project 

OD-12, Progress Report to Feb. 7, 1943, Pennsylvania 
State College, Feb. 13, 1943. Div. 8-101.2-M3 

28. Determination of Water in RDX and Composition B, 
Eugene H. Eyster, and M. A. Paul, OSRD 1234, OEMsr- 
202, Service Project OD-01, Progress Report to Jan. 1, 

1943, ERL, Carnegie Institute of Technology, Mar. 2, 

1943. Div. 8-110.4-M5 

29. The Analysis of RDX-HMX Mixtures, Ralph A. Connor, 
James Cason, Ralph L. Shriner, Frank C. Whitmore, and 
Werner E. Bachmann, OSRD 1711, OEMsr-243, and 
others, Service Project OD-12, Final Report to July 1, 
1943, OEMsr-245, University of Michigan, Pennsylvania 
State College, and others, Aug. 14, 1943. Div. 8-101.2-M4 

30. A Chromatographic Study of RDX and Related Substances, 
Earl W. Mahnberg, OSRD 5943, OEMsr-881, Service 
Project OD-12, CIT, Nov. 13, 1945. Div. 8-602.4-M3 

31. A Chromatographic Investigation of the Impurities in Certain 

Saryiples of Commercial RDX, Earl W. Malmberg, OSRD 
5944, OEMsr-881, Service Project OD-12, CIT, Nov. 13, 
1945. Div. 8-110.4-M7 

32. Studies on the Heat Phenomena Observed in the Preparation 

of RDX by the Bachmann Process, Frank C. Whitmore, 
OSRD 1134, OEMsr-243, Service Project OD-12, Report 
458, to Dec. 3, 1942, Pennsylvania State College, Dec. 8, 
1942. Div. 8-203-M2 


arTTTrrrmnr'r i a tTi 


BIBLIOGRAPHY 


157 


33. The Cause, Prevention and Removal of the Coating Formed 
in the Apparatus Used in the Tennessee Eastman Modifica- 
tion of the Bachmajin Process for the Continuous Prepara- 
tion of RDX, Frank C. Whitmore, OSRD 1121, OEMsr- 
243, Service Project OD-12, Report 443, to Oct. 15, 1942, 
Pennsylvania State College, Dec. 4, 1942. Div. 8-101-Mll 

34. The Effects of Closing Each of the Reactor Feeds in the Con- 

tinuous Process for the Preparation of RDX, Frank C. Whit- 
more, OSRD 1089, OEMsr-243, Service Project OD-12, 
Report 453, to Dec. 1, 1942, Pennsylvania State College, 
Dec. 11, 1942. Div. 8-101-M12 

35. Hazards to the Health of Indiiiduals Working uith RDX (B), 
F. William Simderman, OSRD 4174, OEMsr-962, Service 
Project OD-12, University of Pennsylvania, Sept. 28, 1944. 

Div. 8-101. 1-M3 

30. The Preparation of Explosives from Ethylenediamine, 
Werner E. Bachmann, OSRD 152, XDCrc-87, Service 
Project OD-6, Report 90, to Sept. 15, 1941, University of 
Michigan, Oct. 17, 1941. Div. 8-105-M2 

37. EDNA and Related Compounds, Werner E. Bachmann, 
OSRD 819, NDCrc-87, Service Project OD-6, Report 327, 
to Aug. 15, 1942, University of Michigan, Aug. 24, 1942. 

Div. 8-103-Ml 

38. The Synthesis of Ethylene Urea, Exploratory Work to May 
13, 1943 , C. E. Schweitzer, OSRD 1487, OEMsr-373, Serv- 
ice Project OD-68, Ammonia Department, E. I, duPont 
de Nemours and Company, Inc., June 2, 1943. 

Div. 8-103.1-Ml 

39. Synthesis of Ethyleneurea by the Ethylenediamine -Urea 
Route, Small Scale Development Studies, D. D. Lee and 

H. S. Lecky, OSRD 1793, OEMsr-373, Service Project 
OD-68, Progress Report to July 29, 1943, E. 1. duPont de 
Nemours and Company, Inc., Sept. 11, 1943. 

Div. 8-103.1-M4 

40. The Production of Ethylene Urea by the Ethylenediamine- 

Urea Route, Part I, Process Description, OSRD 1794, 
OEMsr-373, Service Project OD-68, Progress Report to 
Aug. 11, 1943, E. I. duPont de Nemours and Company, 
Inc., Sept. 11, 1943. Div. 8-103. 1-M3 

41. Production of Ethyleneurea by the Ethylenediamine -Urea 

Route, Pilot Plant Studies, C. D. Bell, OSRD 3751, OEMsr- 
373, Service Project OD-68, Report to Apr. 17, 1944, 
E. I. duPont de Nemours and Company, Inc., June 8, 
1944. Div. 8-103.1-M6 

42. Synthesis of Ethyleneurea from Urea and Ethylene Glycol, 
D. D. Lee, OSRD 1619, OEMsr-373, Service Project OD- 
68, Report to May 19, 1943, E. I. duPont de Nemours 
and Company, Inc., July 19, 1943. Div. 8-103. 1-M2 

43. The Synthesis of Ethyleneurea from Urea and Ethylene Glycol, 

Pilot Plant Studies, OSRD 3822, OEMsr-640, Service Pro- 
ject OD-68, E. I. duPont de Nemours and Company, Inc., 
July 4, 1944. Div. 8-103. 1-M8 

44. The Production of Ethyleneurea; Step 4) Synthesis from 

Ethylenediamine and Carbon Dioxide, OSRD 3080, OEMsr- 
373, Service Project OD-68, Progress Report to Nov. 23, 
1943, Ammonia Department, E. I. duPont de Nemours 
and Company, Inc., Jan. 6, 1944. Div. 8-103. 1-M5 

45. Synthesis of Ethyleneurea from Ethylenediamine and Carbon 
Dioxide, Pilot Plant Study, H. S. Lecky, OSRD 3851 
OEMsr-373, Service Project OD-68, E. I. duPont de Ne- 
mours and Company, Inc., Sept. 8, 1944. Div. 8-103. 1-M9 

46. Production of Haleite from Ethyleneurea, OSRD 3466, 
OEMsr-765, Service Project OD-68, Final Report to Mar. 

I, 1944, E. I. duPont de Nemours and Company, Inc., 

Apr. 12, 1944. Div. 8-103-M3 

47. The Production of Ethyleneurea from Ethylenediamine and 
Carbon Dioxide, A Preliminary Engineering Study, OSRD 
3857, OEMsr-1118, Service Project OD-68, E. I. duPont 


de Nemours and Company, Inc., July 4, 1944. 

Div. 8-103. 1-M7 

48. The Addition of Oxides of Nitrogen to Ethylene, Kenneth N. 

Campbell, OSRD 1335, OE]Msr-669, Service Project 

OD-68, Report to Mar. 15, 1943, University of Notre 

Dame, Apr. 9, 1943. Div. 8-110.1-M5 

49. The Addition of Oxides of Nitrogen to Ethylene, Kenneth N. 

Campbell, OSRD 1891, OEMsr-669, Service Project 

OD-68, Progress Report to Sept. 15, 1943, University of 
Notre Dame, Oct. 6, 1943. Div. 8-110.1-M6 

50. The Addition of Oxides of Nitrogen to Ethylene, Kenneth N. 

Campbell, OSRD 3984, OEMsr-669, Service Project 

OD-68, Report to Feb. 29, 1944, University of Notre 
Dame, Aug. 8, 1944. Div. 8-103-:M4 

51. The Crystallography of Haleite, Alfred T. Blomquist, OSRD 
2055, OEMsr-193, Service Project OD-68, Final Report to 
Nov. 15, 1943, Cornell University, Nov. 25, 1943. 

Div. 8-110.3-M5 

52. Compilation of Data on Organic Explosives, A. H. Blatt, 
OSRD 2014, OEMsr-741, Service Projects NO-BIO and 
OD-01, Queens College, Feb. 29, 1944. Div. 8-200-M2 

53. DINA and Related Compounds, Alfred T. Blomquist, 
OSRD 5155, OEMsr-193, Service Project NO-135, Report 
to May 31, 1945, Cornell University, June 9, 1945. 

Div. 8-104-M3 

54. DINA and Related Compounds, Ralph L. Shriner, OSRD 

5156, OEMsr-701, Service Project NO-135, Indiana Uni- 
versity, Aug. 7, 1945. Div. 8-104-M5 

55. DINA and Related Compounds, Marvin Carmack, OSRD 

5157, OEMsr-646, Service Project NO-135, University of 

Pennsylvania, June 19, 1945. Div. 8-104-M4 

56. DINA, Process Development and Semiworks Production, 

OSRD 5975, OEMsr-1332, Service Project NO-135, East- 
ern Laboratory, E. I. duPont de Nemours and Company, 
Inc., Oct. 12, 1945. Div. 8-104-M6 

57. Organic Development Problems, Compiled by H. J. Fisher, 

Service Projects NO-BIO, NO-117, and others. Interim 
Reports ODP-18 through ODP-27, covering period from 
Apr. 15, 1944 to Feb. 15, 1945, May 1944 to February 
1945. Div. 8-104-Ml 

58. Special Propellants, Compiled by J. F. Kincaid, George B. 

Kistiakowsky, and H. J. Fisher, Service Projects OD-05, 
OD-44 and others. Interim Reports SP-30 through SP-35, 
covering period from Feb. 15, 1945 to Aug. 15, 1945, 
September 1942 to August 1945. Div. 8-607-Ml 

59. Preparaiion of DINA, Safety Tests, OSRD 4882, OEMsr- 
1332, Service Project NO-135, Eastern Laboratory, E. I. 
duPont de Nemours and Company, Inc., Mar. 31, 1945. 

Div. 8-104-M2 

60. Nitroamides, Roger Adams and C. S. iMarvel, OSRD 86, 
Service Project OD-15, Report 23, to July 24, 1941, 
NDCrc-48, University of Illinois, Aug. 24, 1941. 

Div. 8-105-Ml 

61. Color Reactions of RDX, HMX and TNT, The Preparation 
of Various Nitramines, Ralph L. Shriner, OSRD 2054, 
OEMsr-701, Service Projects OD-6 and OD-12, Progress 
Report to Nov. 1, 1943, Indiana University, Nov. 25, 1943. 

Div. 8-105-M5 

62. Nitration of Melamine, Frank C. Whitmore, OSRD 351, 
NDCrc-66, Service Project OD-12, Report 173, to Jan. 1, 
1942, Pennsylvania State College, Jan. 29, 1942. 

Div. 8-110.1-M4 

63. Studies on Nitramines and Nitrosohydroxylamines, James 

Cason, OSRD 3567, OEMsr-790, Service Project OD-6, 
Report to Mar. 1, 1944, Vanderbilt University, May 3, 
1944. Div. 8-105-M6 

64. Preparation and Testing of Explosives, compiled by George 
B. Kistiakowsky and H. J. Fisher, Service Projects OD-01, 


C Un lUDKyi'i a| ; 


158 


BIBLIOGRAPHY 


OD-04, and others, Interim Report PT-7, covering period 
from Feb. 15 to Mar, 15, 1943, September 1942 to August 
1945. Div. 8-109-M3 

65. Preparation and Testing of Explosives, compiled by George 
B. Kistiakowsky and H. J. Fisher, Service Projects OD-01, 
OD-04, and others. Interim Report PT-8, covering period 
from Mar. 15 to Apr. 15, 1943, September 1942 to August 
1945. Div. 8-109-M3 

60. “Quelques Nitramines et Leur Preparation,” A. P. N. 
Franchimont and E. A. Klobbie, Reciieil Travaux Chimiqiies, 
Leide, Vol. 7, 1888, pp. 343-357. 

67. A Preparation and Properties of Dinitroxydiethyl-nitra- 
mine, [>ina, (Canadian Report), \V. J. Chute and George 
F. Wright, Project XR-19, University of Toronto, June 1, 

1943, 

68. Certain Aliphatic Nitramines and Related Compounds, Alfred 
T. Blomquist, OSRD 4134, OEMsr-193, Service Project 
OD-6, Cornell University, Nov. 29, 1944. Div. 8-106-M5 

69. Preparation and Reactions of Aliphatic Amines, John R. 

Johnson, OSRD 161, NDCrc-23, Service Projects CWS-4 
and OD-5, Report 99, to Sept. 15, 1941, Cornell University, 
Oct. 27, 1941. Div. 8-105-M3 

70. Studies Relatmg to Aliphatic Nitramines, John R. Johnson, 

OSRD 915, OEMsr-193, Service Projects OD-6 and NO- 
BIO, Report 382, to Sept. 15, 1942, Cornell University, 
Oct. 7, 1942. Div. 8-106-M4 

71. Preparation and Testing of Explosives, compiled by George 

B. Kistiakowsky and H. J. Fisher, Service Projects OD-01, 
OD-04, and others. Interim Report PT-4, covering period 
from Nov. 15 to Dec. 15, 1942, September 1942 to August 
1945. Div. 8-109-M3 

72. The Ultraviolet Absorption Spectra of Nitramines, Nitro- 

sohydroxylamines and Their Salts, Marvin Carmack, and 
J. J. Leavitt, OSRD 3565, OEMsr-646, Service Projects 
OD-6 and OD-02, Report to Apr. 1, 1944, University of 
Pennsylvania, May 3, 1944. Div. 8-105-M7 

73. British Report, AC-5058/ROX-70, Oct. 15, 1943. 

74a. Organic Development Problems, compiled by H. J. Fisher, 
Service Projects NO-BIO, NO-117, and others. Interim Re- 
j)ort ODP-23, covering period from Sept. 15 to Oct. 15, 

1944, May 1944 to February 1945, p. 72. Div. 8-104-Ml 

74b. Ibid., p. 70. 

75. Preparation and Testing of Explosives, compiled by George 
B. Kistiakowsky and H. J. Fisher, Service Projects OD-01, 
OD-04, and others. Interim Report PT-25, covering period 
from Aug. 15 to Sept. 15, 1944, September 1942 to August 

1945, p. 52. Div. 8-109-M3 

76. The Synthesis of Certain Aliphatic Nitro Compounds, H. B. 

Hass, OSRD 154, NDCrc-35, Service Project OD-2, Re- 
port 92, to Sept. 15, 1941, Purdue University, Oct. 18, 
1941. Div. 8-106-Ml 

77. The Preparation of Nitroparaffins, OSRD 2016, OEMsr- 

371, Service Project OD-2, Final Report to Dec. 11, 1942, 
Purdue University, Nov. 15, 1943. Div. 8-800-Ml 

78. Preparation and Reactions of Nitroform, Charles D. Hurd, 
OSRD 144, NDCrc-7, Service Project OD-11, Report 82, 
to Sei)t. 15, 1941, Northwestern University, Sept. 20, 1941. 

Div. 8-110.1-Ml 

79. The Preparation of Tetranitromethane, Charles D. Hurd, 
OSRD 334, NDCrc-7, Service Project OD-11, Serial 164, 
Northwestern University, Jan. 20, 1942. Div. 8-110.11-M3 

80. Preparation of Nitro Compounds, John R. Johnson, OSRD 
160, NDCrc-23, Service Project OD-5, Report 98, to Sept. 
15, 1941, Cornell University, Oct. 27, 1941. Div. 8-106-M2 

81. Preparation of Trinitrobenzene from Benzene via Picryl 

Chloride, Roger Adams and C. S. Marvel, OSRD 312, 
Oh]Msr-48, Service Project OD-5, Serial 141, University 
of Illinois, Dec. 15, 1941. Div. 8-110.11-M2 


82. The Nitration of Benzene and Toluene in the Absence of Sul- 
furic Acid According to a Process Submitted by the Autoxy- 
gen Company, Robert C. Elderfield, OSRD 1192, OEMsr- 
137, Service Project OD-9, Columbia University, Feb. 11, 

1943. Div. 8-110.12-Ml 

83. Kinetic Studies on the Nitration Process, Robert C. Elder- 

field and Louis P. Hammett, OSRD 1154, OEMsr-305, 
Service Project OD-9, Report to Sept. 30, 1942, Columbia 
University, Jan. 25, 1943. Div. 8-110.13-M3 

84. The Kinetics of Nitration, M. S. Kharasch, and F. H. 

Westheimer, OSRD 295, NDCrc-4, Service Project OD-9, 
Report 146, to Oct. 1, 1941, University of Chicago, Dec. 
29, 1941. Div. 8-110.13-Ml 

85. Kinetics of Nitration, Preparation of Trinitroethylbenzene, 
M. S. Kharasch and F. H. Westheimer, OSRD 285, 
NDCrc-4, Service Project OD-9, Progress Report 147, to 
Oct. 1, 1941, University of Chicago, Dec. 29, 1941. 

Div. 8-110.13-M2 

86. Preparation of Polynitronaphthalenes, Tenney L. Davis, 

OSRD 115, NDCrc-12, Service Project OD-13, Serial 53, 
MIT, June 27, 1941. Div. 8-1 10.1 1-Ml 

87. Canadian Report, Project CE-12, University of Toronto, 
Jan. 14, 1941. 

88. The Direct Conversion of Benzene to Picric Acid, Roger 

Adams and C. S. Marvel, OSRD 141, NDCrc-48, Service 
Project OD-15, Serial 79, University of Illinois, Sept. 20, 
1941. Div. 8-107-Ml 

89. German Patents 194,883 (1906); 214,045 (1907), Wolfen- 
stein and Boters. 

90. Organic Development Problems, compiled by George B. 
Kistiakowsky and H. J. Fisher, Service Projects OD-68, 
NO-117, and others. Interim Reports ODP-1 through 
ODP-17, covering period from Nov. 15, 1942 to Apr. 15, 

1944, December 1942 to April 1944. Div. 8-110-Ml 

90a. Ibid., Interim Report ODP-9, July 15 to Aug. 15, 1943, 

p. 8. 

90b. Ibid., Interim Report ODP-15, Jan. 15 to Feb. 15, 1944, 

p. 12. 

90c. Ibid., Interim Report ODP-8, June 15 to July 15, 1943, 
p. 23. 

91. The Oxy nitration of Benzene to 2-, 4-Dinitro phenol, Werner 
E. Bachmann, OSRD 4026, OEMsr-245, Service Project 
NO-117, University of Michigan, Feb. 28, 1945. 

Div. 8-110.12-M4 

92. The Oxynitration of Benzene to Nitrophenols, Marvin Car- 
mack, OSRD 4025, OEMsr-646, Service Project NO-117, 
University of Pennsylvania, Oct. 5, 1945. 

Div. 8-110.12-M4 

93. The Oxynitration Reaction, F. H. Westheimer, OSRD 3154, 
OEMsr-875, Service Project NO-117, Report to Jan. 13, 
1944, University of Chicago, Jan. 19, 1944. 

Div. 8-110.1-M7 

94. The Kinetics of the Nitration of Phenols, F. H. West- 

heimer, J. E. Bloom, and others, OSRD 4024, OEMsr- 
875, Service Project NO-117, University of Chicago, 
Oct. 9, 1944. Div. 8-110.12-M2 

95. The Preparation of Sugar Alcohols and Glycosides for Ni- 
tration Studies, M. L. Wolfrom, OSRD 147, NDCrc-43, 
Service Project OD-4, Final Report 85, to Sept. 15, 1941, 
Ohio State University, Oct. 7, 1941. Div. 8-110.2-M2 

96. The Tetritols, A Literature Survey, M. L. Wolfrom, OSRD 
146, NDCrc-43, Service Project OD-4, Report 84, to 
Sept. 15, 1941, Ohio State University, Oct. 6, 1941. 

Div. 8-110.2-M2 

97. The Preparation of Anhydroenneaheptitol, M. L. Wolfrom, 

OSRD 145, NDCrc-43, Service Project OD-04, Final 
Report 83, to Sept. 15, 1941, Ohio State University, 
Oct. 4, 1941. Div. 8-110.2-Ml 


U7>.2uamZ Ur i a i.\ 


BIBLIOGRAPHY 


159 


98. Preparation and Testing of Explosives, compiled by George 

B. Kistiakowsky and H. J. Fisher, Service Projects 

OD-01, OD-04, and others, Interim Report PT-2, cover- 
ing period from Sept. 15 to Oct. 15, 1942, September 1942 
to August 1945. Div. 8-109-M3 

99. Preparation of Pentaerythritol, M. L. Wolfrom, OSRD 
148, NDCrc-43, Service Project OD-4, Final Report 86, 
to Aug. 13, 1941, Ohio State University, Oct, 7, 1941. 

Div. 8-110.2-M4 

100. The Preparation of Pentaerythritol, Robert C. Elderfield, 
OSRD 1804, OEIMsr-224, Service Project OD-58, Report 
to Sept. 1, 1943, Columbia University, Sept. 16, 1943. 

Div. 8-110.2-M5 

101. “Uber die Synthese von Ketoalkoholen und Mehrwerti- 
gen Alkoholen aus Cyklischen Ketonen und Formalde- 
hyde,” C. Mannich and W. Brose, Berichte der Deutschen 
Chemischen Gesellschaft, Vol. 56, Part I, 1923, pp. 833-844. 

102. “Nitrates of Cyclic Keto Alcohols Explosives,” Walter 
Friederich and Karl Flick, German Patent 509,118, 
Oct. 11, 1929 [Chemical Abstracts, Vol. 25, 1931, p. 819]. 

103. “Explosive Nitrates of Tetramethyl-o-cyclopentanone, 
Tetramethyl-o-cyclohexanone, Tetramethyl-o-cyclopen- 
tanol, Tetramethyl-o-cyclohexanol,” Walter Friederich, 
U.S. Patent 1,962,065, June 5, 1934 [Chemical Abstracts, 
Vol. 28, 1934, p. 4910]. 

104. Evaluation of Fivonite as a High Explosive, Eugene H. 
Eyster and D. P. MacDougall, OSRD 5627, OEMsr-202, 
Service Projects OD-01 and NO-290, ERL, Carnegie In- 
stitute of Technology, Nov. 5, 1945. Div. 8-108-M3 

105. Preparation and Properties of Fivonite, Amos Turk, OSRD 

1767, OEMsr-202, Service Project OD-01, Report to 
Aug. 2, 1943, ERL, Carnegie Institute of Technology, 
Sept. 3, 1943. Div. 8-108-Ml 

106. Pnocess Desigyi of a Fivone Pilot Plant, OSRD 3054, 

OEMsr-1126, Service Projects OD-01 and OD-04, Final 
Report to Nov. 24, 1943, Phillips Petroleum Company, 
Dec. 30, 1943. Div. 8-108-M2 

107. Preparation of DEGN and Double-Base Powder Duplicat- 

ing a German Rocket Propellant, OSRD 4212, OEMsr-763, 
Service Project OD-14, Eastern Laboratory, Explosives 
Department, E. I. duPont de Nemours and Company, 
Inc., Oct. 4, 1944. Div. 8-607.3-M5 

108. Explosive Polymers, C. S. Marvel, OSRD 875, OEMsr- 
300, Service Project NO-BIO, Report 364, to Sept. 15, 
1942, University of Illinois, Sept. 17, 1942. 

Div. 8-107-M2 

109. Preparation of Nitro Compounds, John R. Johnson, OSRD 
160, NDCrc-23, Service Project OD-5, Report 98, to 
Sept. 15, 1941, Cornell University, Oct. 27, 1941. 

Div. 8-106-M2 

110. Combustible Nitro Polymers, OSRD 3324, OEMsr-643, 

Service Project OD-01, Report to Feb. 15, 1944, Rohm & 
Haas Company, Mar. 6, 1944. Div. 8-106-M3 

111. The Preparation and Plastic Properties of Small Batches of 
Double- Base Powders Containing Nitro Esters of Maleic 
Acid, Earl O. Wilson, OSRD 4430, OEMsr-881, Service 
Projects OD-158 and NO-274, CIT, Dec. 1, 1944. 

Div. 8-607.2-Ml 

112. Study of the British Continuous Tetnjl Process, Robert C. 
Elderfield, OSRD 661, OEMsr-202, Service Project 
OD-04, Final Report 278, to June 10, 1942, Carnegie 
Institute of Technology, June 25, 1942. Div. 8-607. 3-M3 

113. Explosives from Hydroxy and Amino Compounds, Robert 

C. Elderfield, OSRD 158, NDCrc-24, Service Project 
OD-7, Serial 96, Columbia University, Oct. 27, 1941. 

Div. 8-109-Ml 

114. Explosives from Hydroxy and Amino Compounds, Robert 
C. Elderfield, OSRD 907, OEMsr-137, Service Project 


OD-7, Report 377, to Sept. 15, 1942, Columbia Uni- 
versity, Sept. 30, 1942. Div. 8-109-M4 

115. Aromatic Aliphatic Nitro Compounds and Nitrate Esters, 

Louis F. Fieser, OSRD 176, NDCrc-5, Service Project 
OD-8, Report 114, to Sept. 15, 1941, Harvard University, 
Nov. 13, 1941. Div. 8-106-M3 

116. The Nitration of Furans, Henry Gilman, OSRD 350, 
NDCrc-19, Service Project OD-1, Report 172, to May 1, 

1941, Iowa State College, Jan. 28, 1942. Div. 8-110.1-M3 

117. The Reactions of Xylene with Aluminum Chloride, L. 1. 
Smith, OSRD 333, NDCrc-17, Service Project OD-10, 
Serial 163, University of Minnesota, Jan. 20, 1942. 

Div. 8-110.1-M2 

118. Preparation of Aminoguanidine Sulfate, G. B. L. Smith, 

OSRD 138, NDCrc-22, Service Project OD-3, Report 
76, to Aug. 1, 1941, Polytechnic Institute of Brooklyn, 
Sept. 17, 1941. Div. 8-110.4-Ml 

119. The Preparation and Properties of Plastic High Explosives, 

Eugene H. Eyster, OSRD 5631, OEMsr-202, Service Pro- 
ject OD-04, Carnegie Institute of Technology, Jan. 15, 
1946. Div. 8-109-M9 

120. Beeswax Substitutes for Phlegmatization of Cyclonite, D. P. 
MacDougall, OSRD 313, OEMsr-11, Service Project 
OD-04, Progress Report 150, to Dec. 30, 1941, Carnegie 
Institute of Technology, Jan. 10, 1942. Div. 8-801-Ml 

121. PEP-2, PETN Plastic Explosive, Eugene H. Eyster and 

M. A. Paul, OSRD 3240, OEMsr-202, Service Project 
OD-04, ERL, Carnegie Institute of Technology, Feb. 11, 
1944. Div. 8-109-M6 

122. Beeswax Substitutes for Phlegmatization of Cyclonite, D. P. 
MacDougall, OSRD 397, OEMsr-11 and OEMsr-202, 
Service Project OD-04, Progress Report 187, to Feb. 15, 

1942, Carnegie Institute of Technology, Feb. 23, 1942. 

Div. 8-801-M2 

123. Beeswax Substitutes for Phlegmatization of Cyclonite, D. P. 

MacDougall, OSRD 486, OEMsr-202, Service Project 
OD-04, Serial 218, Carnegie Institute of Technology, 
Apr. 4, 1942. Div. 8-80 1-M3 

124. The Preparation and Properties of RDX, Composition A, 
Eugene H. Eyster and C. A. Weltman, OSRD 5626, 
OEMsr-202, Service Projects NO-290 and OD-01, ERL, 
Carnegie Institute of Technology, Dec. 29, 1945. 

Div. 8-101-M15 

125. Specifications of the Physical Properties of Desensitizing 

Waxes for Uses in Explosives, Eugene H. Eyster, OSRD 
5633, OEMsr-202, Service Projects OD-04, NO-232 and 
NO-290, ERL, Carnegie Institute of Technology, Jan. 2, 
1946. Div. 8-801-M5 

126. Composition B, Cyclotol, Eugene H. Eyster and M. A. 
Paul, OSRD 1167, OEMsr-202, Service Projects OD-01, 
OD-04 and NO-B38, Progress Report to Jan. 15, 1943, 
ERL, Carnegie Institute of Technology, Jan. 29, 1943. 

Div. 8-101. 1-M2 

127. The Viscosity of Explosive Slurries; Part I, Experimental 

Methods and Results, Eugene H. Eyster, A. A. Layton, 
and M. A. Paul, OSRD 3663, OEMsr-202, Service Project 
OD-04, ERL, Carnegie Institute of Technology, May 22, 
1944. Div. 8-803-Ml 

128. The Viscosity of Explosive Slurries; Part II, Experimen- 

tal Methods, Determination of Stress-Rate Curves; Part III, 
The Improvement of Explosive Slurries by Surface Active 
Agents, A. A. Layton and Eugene H. Eyster, OSRD 5625, 
OEMsr-202, Service Project OD-04, ERL, Carnegie In- 
stitute of Technology, Nov. 9, 1945. Div. 8-803-M2 

129. A Comparison of Cyclotol, Pentolite and Ednatol, OSRD 

1364, OEMsr-202, Service Project OD-01, Report to 
Apr. 1, 1943, ERL, Carnegie Institute of Technology, 
Apr. 24, 1943. Div. 8-109-M5 


160 


BIBLIOGRAPHY 


130. Studies of the Desensitization of Torpex-2 and of the Sensi- 

tivity of HEX, Eugene H. Eyster, OSRD 5743, OEMsr- 
202, Service Project NO-232, ERL, Carnegie Institute 
of Technology, Jan. 2, 1945. Div. 8-202-M12 

131. Waxes for HEX, F. H. Westheimer, OSRD 5573, OEMsr- 
202, Service Projects NO-231 and NO-232, ERL, Car- 
negie Institute of Technology, Oct. 3, 1945. 

Div. 8-80 1-M4 

132. Emulsifiers for HEX and HEX-1, F. H. Westheimer and 

J. W. Dawson, OSRD 5597, OEMsr-202, Service Project 
NO-232, ERL, Carnegie Institute of Technology, Nov. 
20, 1945. Div. 8-802-Ml 

133. Underwater Explosives Research, D. P. MacDougall, 
OSRD 1035, OEMsr-202, Service Projects OD-03 and 
OD-04, Division 8, First Progress Report 429, Carnegie 
Institute of Technology, Nov. 18, 1942. Div. 2-131. 1-Ml 

134. Preparation and Testing of Explosives, compiled by George 

B. Kistiakowsky and H. J. Fisher, Service Projects OD-01, 
OD-04, and others. Interim Report PT-23, covering 
period from June 15, to July 15, 1944, September 1942 to 
August 1945, p. 26. Div. 8-109-M3 

135. Preparation and Testing of Explosives, compiled by George 

B. Kistiakowsky and H. J. Fisher, Service Projects 
OD-01, OD-04, and others. Interim Report PT-24, cover- 
ing period from July 15 to Aug. 15, 1944, September 1942 
to August 1945, p. 18. Div. 8-109-M3 

136. Preparation and Testing of Explosives, compiled by George 

B. Kistiakowsky and H. J. Fisher, Service Projects 
OD-01, OD-04, and others. Interim Report PT-25, cover- 
ing period from Aug. 15 to Sept. 15, 1944, Sept. 1942 to 
Aug. 1945, p. 45. Div. 8-109-M3 

137. High Desensitized Cast Explosives, Eugene H. Eyster, 

OSRD 5628, OEMsr-202, Service Projects NO-232 and 
NO-290, ERL, Carnegie Institute of Technology, Jan. 22, 
1946. Div. 8-202-M16 

138. The Gas Evolution from Torpex, F. H. Westheimer and 

J. W. Dawson, OSRD 4085, OEMsr-202, Service Projects 
OD-01, OD-04, and NO-231, ERL, Carnegie Institute of 
Technology, Sept. 1, 1944. Div. 8-109-M8 

139. The Gas Evolution from TNT- Aluminum, Amos Turk, 

OSRD 4339, OEMsr-202, Service Projects OD-01, OD-04, 
and NO-231, ERL, Carnegie Institute of Technology, 
Nov. 14, 1944. Div. 8-203. 1-Ml 

140. The Gas Evolution from DEX, Amos Turk and Earl Hel- 

lerstein, OSRD 4715, OEMsr-202, Service Projects 
OD-01, OD-04, and NO-231, ERL, Carnegie Institute of 
Technology, Feb. 19, 1945. Div. 8-203. 1-M2 

141. The Gas Evolution from Minol, J. W. Dawson and F. H. 

Westheimer, OSRD 5595, OEMsr-202, Service Projects 
OD-01, OD-04, and NO-231, ERL, Carnegie Institute of 
Technology, Nov. 8, 1945. Div. 8-203. 1-M3 


Chapter 2 

1. Some Properties of NENO and MNO as Explosives, D. P. 

MacDougall, OSRD 560, OEMsr-202, Service Project 
OD-01, Report 240, to May 1, 1942, Carnegie Institute of 
Technology, May, 8, 1942. Div. 8-109-M2 

2. A Comparison of Cyclotol, Pentolite and Ednatol, OSRD 

1364, OEMsr-202, Service Project OD-01, Report to 
Apr. 1, 1943, ERL, Carnegie Institute of Technology, 
Apr. 24, 1943. Div. 8-109-M5 

3. Evaluation of Fivonite as a High Explosive, Eugene H. 
Eyster and D. P. MacDougall, OSRD 5627, OEMsr-202, 
Service Projects OD-01 and NO-290, ERL, Carnegie In- 
stitute of Technology, Nov. 5, 1945. Div. 8-108-M3 


4. Report on Minol and Torpex, Committee on Fillings for 
Aerial Eombs, OSRD 4243, NDRC Divisions 2 and 8, 
October 1944. 

5. The Effect of Heat on Confined Explosives, The M-35 Five- 

inch Projectile, Various Pure Explosives and Explosive Mix- 
tures, H. A. Strecker and E. C. Broge, OSRD 3956, OEMsr- 
202, Service Project NO-201, ERL, Carnegie Institute of 
Technology, July 28, 1944. Div. 8-203. 2-M4 

6. The Effect of Mechanical Stresses on High Explosives, 

P. W. Bridgman, OSRD 64, Serial 1, Harvard University, 
Dec. 19, 1940. Div. 8-202-Ml 

7. Development of Inert Materials to Simidate Explosives, 

J. B. Tepe, OSRD 6362, OEMsr-1467, Service Project 
NO-231, E. 1. duPont de Nemours and Company, Inc., 
Dec. 4, 1945. Div. 8-110-M2 

8. Chemical Tests for New Explosives, Russell IMcGill, OSRD 

787, OEMsr-202, Service Project OD-01, Report 305, to 
July 1, 1942, Carnegie Institute of Technology, Aug. 11, 
1942. Div. 8-20 1-Ml 

9. Methods of Stability Testing, Hyman Henkin, OSRD 3401, 

OEMsr-202, Service Projects OD-01 and OD-04, Report 
as of Jan. 1, 1944, ERL, Carnegie Institute of Technology, 
Mar. 22, 1944. Div. 8-201-M5 

10. Deter7nination of Explosion Temperatures, Hyman Henkin, 

OSRD 1986, OEMsr-202, Service Projects OD-01 and OD- 
04, Report to Oct. 25, 1943, ERL, Carnegie Institute of 
Technology, Nov. 4, 1943. Div. 8-203.2-M4 

11. Studies on the Stability of PETN and Pentolite, S. D. 
Brewer, OSRD 3983, OEMsr-202, Service Project OD-58, 
ERL, Carnegie Institute of Technology, Aug. 8, 1944. 

Div. 8-109-M7 

12. The Stability of PETN and Pentolite, Russell McGill, 

OSRD 1414, OEMsr-202, Service Project OD-58, Report 
to Apr. 1, 1943, Carnegie Institute of Technology, 
May 14, 1943. Div. 8-201-M3 

13. Studies Related to the Stability of PETN, Alfred T. Blom- 

quist and James F. Ryan, Jr., OSRD 3566, OEMsr-193, 
Service Project OD-58, Report to Feb. 29, 1944, Cornell 
University, May 3, 1944. Div. 8-201-M6 

14. Stability of Ethylenedinitr amine, Haleite and Related Ni- 
tramines, Hyman Henkin, OSRD 1734, OEMsr-202, Service 
Project OD-68, Progress Report to Aug. 1, 1943, ERL, 
Carnegie Institute of Technology, Aug. 21, 1943. 

Div. 8-103-M2 

15. Kinetics of Decomposition of Various Explosives, Hyman 

Henkin, OSRD 3856, OEMsr-202, Service Projects OD-01 
and OD-04, ERL, Carnegie Institute of Technology, 
July 4, 1944. Div. 8-110.13-M4 

16. Methods of Physical Testing, D. P. MacDougall, OSRD 

804, OEMsr-202, Service Project OD-01, Report 307, 
Aug. 1, 1942, Carnegie Institute of Technology, Aug. 11, 
1942. Div. 8-200-Ml 

17. Evaluation of Explosives Submitted to the Explosives Research 

Laboratory in 194-1, Russell McGill, OSRD 830, OEMsr- 
202, Service Project OD-01, Serial 329, Carnegie Institute 
of Technology, Aug. 25, 1942. Div. 8-201-M2 

18. Studies of the Sensitivity of Explosives to Eullet Impact, 

OSRD 3149 (Part of Collection appearing in OSRD 3156), 
Service Project OD-01, ERL, December 1943. 

Div. 8-202-M4 

19. Sensitivity of Explosives to Projectile Impact, Eugene H. 

Eyster, George B. Kistiakowsky, and others, OSRD 3156, 
ERL, Jan. 1, 1944. Div. 8-202-M4 

20. The Sensitivity of Various General Purpose Eombs and 
Simulated Rocket Motors to Projectile Impact, W. H. Rogers 
and Eugene H. Eyster, OSRD 5024, OEMsr-202, Service 
Projects OD-04, NO-231 and NO-232, ERL, Carnegie In- 
stitute of Technology, May 2, 1945. Div. 8-202-M8 


jitoyFinHy'iM Ai, j 


BIBLIOGRAPHY 


161 


21. Physical Testing of Explosives; Pari II, Sensitivity Studies 

ivith the Drop-Weight Impact Machine, Eugene H. Eyster 
and R. F. Davis, OSRD 5744, OEMsr-202, Service Pro- 
jects OD-01 and NO-290, ERL, Carnegie Institute of Tech- 
nology, Dec. 27, 1945. Div. 8-202-M10 

22. Physical Testing of Explosives; Part I, The Sensitivity of 

Explosives to Bullet Impact, Eugene H. Eyster and W. H. 
Rogers, OSRD 5745, OEi\Isr-202, Service Projects NO- 
290, OD-01, and NO-231, ERL, Carnegie Institute of 
Technology, Nov. 20, 1945. Div. 8-202-M9 

23. Physical Testing of Explosives; Part III, Miscellaneous 

Sensitivity Tests, Performance Tests, L. C. Smith and 
Eugene H. Eyster, OSRD 5746, OEIVIsr-202, Service 
Projects OD-01 and NO-290, ERL, Carnegie Institute of 
Technology, Dec. 27, 1945. Div. 8-202-IVIll 

24. Bullet Impact Tests of Demolition Packs and Reinforced 
Detonating Cord, W. H. Rogers, OSRD 5747, OEMsr-202, 
Service Projects NO-290 and OD-01, ERL, Carnegie In- 
stitute of Technology, Jan. 18, 1946. Div. 8-202-M15 

25. The Sensitiirity to Bullet Impact of Aerial Depth Bombs 

Loaded with TNT and with Various IIBX’s, W. H. 
Rogers and Eugene H. Eyster, OSRD 5748, OEMsr-202, 
Service Project NO-232, ERL, Carnegie Institute of Tech- 
nology, Jan. 15, 1946. Div. 8-202-M13 

26. Sensitiveness of High Explosives, OSRD 1288, OEMsr-719, 

Service Project OD-01, Report to Mar. 1, 1943, Hercules 
Powder Company, Mar. 23, 1943. Div. 8-202-M3 

27. A Method of Measuring the Sensitiveness of High Explosives 

to Frictional Impact, J. G. Fox, OSRD 3185, OEMsr-719, 
Service Project OD-01, Hercules Powder Company, Jan. 

27, 1944. Div. 8-202-M5 

28. Sensitiveness of High Explosives, Part II, OSRD 3991, 

OEMsr-719, Service Project OD-01, Hercules Powder 
Company, Aug. 9, 1944. Div. 8-202-M6 

29. Sensitiveness of High Explosives, Part III, OSRD 4962, 

OEMsr-719, Service Project OD-01, Hercules Powder 
Company, Apr. 21, 1945. Div. 8-202-M7 

30. Sensitiveiiess of High Explosives, J. M. Downard, J. G. 

Fox, and others, OSRD 5632, OEMsr-719, Service Pro- 
jects OD-01 and NO-290, Hercules Powder Company, 
Jan. 17, 1946. Div. 8-202-M14 

31. Sensitiveness of High Explosives, J. M. Downard, OSRD 

6()27, OEMsr-719, Service Projects OD-01 and NO-290, 
Fifth Formal Progress Report, Hercules Powder Company, 
Feb. 28, 1946. Div. 8-202-M17 

32. Sensitiveness of High Explosives, J. M. Downard and 

R. \V. Lawrence, OSRD 6629, OEMsr-719, Service Pro- 

jects OD-01 and NO-290, Hercules Powder Company, 
Mar. 30, 1946. Div. 8-202-M18 

33. The Hydrodynamic Theory of Detonation and Shock W aves, 
George B. Kistiakowsky and E. Bright Wilson, Jr., 
OSRD 114, NDCrc-30, Service Projects OD-02 and OD- 
03, Final Report 52, Harvard University, Aug. 15, 1941. 

Div. 2-131-Ml 

34. The Chemical Reaction in a Detonation Wave, Henry Eyr- 
ing, Richard E. Powell, G. H. Duffy and P. B. Parlin, 
OSRD 3796, OEIMsr-957, Service Projects NO-224 and 
OD-02, Princeton University, June 17, 1944. Div. 8-502-M4 

35. A Rotating-Drum Camera for the Optical Study of Detona- 
tions, D. P. MacDougall and G. H. Messerly, OSRD 682, 
OEMsr-202, Service Project OD-04, Serial 285, Carnegie 
Institute of Technology, July 8, 1942. Div. 8-40 1-Ml 

36. Construction and Operation of the Rotating-Mirror Camera, 

S. J. Jacobs, OSRD 5614, OEMsr-202, Service Projects 

NO-291 and OD-04, ERL, Carnegie Institute of Tech- 
nology, Jan. 2, 1946. Div. 8-401-M4 

37. The Effect of Charge Wrapping on the Optical Records of 
Detonating Explosives, G. H. Messerly, OSRD 1413, 


OEMsr-202, Service Project OD-04, Progress Report to 
April 15, 1943, ERL, Carnegie Institute of Technology, 
May 14, 1943. Div. 8-403-Ml 

38. The Flash Photography of Detonating Explosives, G. H. 
Messerly, OSRD 1488, OEMsr-202, Service Project OD- 
02, Progress Report to May 1, 1943, ERL, Carnegie In- 
stitute of Technology, June 3, 1943. Div. 8-401-M2 

39. Studies Pertaining to Measurement of Temperature, T. P. 

Cotter and S. J. Jacobs, OSRD 5618, OEMsr-202, Serv- 
ice Project NO-291, ERL, Carnegie Institute of Tech- 
nology, Jan. 22, 1946. Div. 8-401-M6 

40. The Rate of Detonation of Various Explosive Compounds, 

G. H. Messerly, OSRD 1219, OEMsr-202, Service Proj- 
ects OD-01 and OD-04, ERL, Carnegie Institute of Tech- 
nology, Feb. 22, 1943. Div. 8-501-M3 

41. The Rate of Detonation of Various Explosive Compounds 
and Mixtures, M. D. Hurwitz, OSRD 5611, OEMsr-202, 
Service Projects OD-04 and NO-291, ERL, Carnegie 
Institute of Technology, Jan. 15, 1946. Div. 8-501-M8 

42. Initiation, Propagation and Luminosity Studies of Liquid 
Explosives, H. A. Strecker, OSRD 5609, OEMsr-202, 
Service Projects OD-04 and NO-291, ERL, Carnegie In- 
stitute of Technology, Dec. 3, 1945. Div. 8-304-M4 

43. Rate Studies on Primacord Detonating Fuse, H. A. 

Strecker, OSRD 5610, OEMsr-202, Service Projects OD- 
02 and NO-291, ERL, Carnegie Institute of Technology, 
Oct. 23, 1945. Div. 8-705-Ml 

44. Revised Method of Predicting the Detonation Velocities m 

Solid Explosives, Stuart R. Brinkley, Jr., and E. Bright 
Wilson, Jr., OSRD 905, NDCrc-168, Service Project 
OD-02, Report 374, to Sept. 12, 1942, Harvard Uni- 
versity, Sept. 28, 1942. Div. 8-501-M2 

45. Calculation of the Detonation Velocities of Some Pure Ex- 
plosive, Stuart R. Brinkley, Jr., and E. Bright Wilson, 
Jr., OSRD 1707, NDCrc-168, Service Projects OD-02 
and NO-144, Harvard University, Aug. 12, 1943. 

Div. 8-501-M4 

46. The Detonation Velocity of Explosive Mixtures Containing 
Ammonium Nitrate, F. J. Martin and G. H. Messerly, 
OSRD 3411, OEMsr-202, Service Project OD-04, ERL, 
Carnegie Institute of Technology, Mar. 24, 1944. 

Div. 8-501-M6 

47. The Effect of Particle Size on the Detonation Velocity of 

Ammonium Picrate, F. J. Martin, Elizabeth M. Boggs, 
and G. H. Messerly, OSRD 1755, OEMsr-202, Service 
Project OD-04, ERL, Carnegie Institute of Technology, 
Aug. 31, 1943. Div. 8-501-M5 

48. Detonation, Fragmentation and Air Blast, compiled by 

George B. Kistiakowsky and H. J. Fisher, Service Pro- 
jects OD-02, OD-03, and others. Interim Report DF-20, 
covering period from July 15 to Aug. 15, 1945, Septem- 
ber 1943 to August 1945. Div. 8-500-M2 

49. Initiation Studies in Solid Explosives, Elizabeth M. Boggs, 
G. H. Messerly and H. A. Strecker, OSRD 5617, OEMsr- 
202, Service Projects NO-291 and OD-04, ERL, Carnegie 
Institute of Technology, Dec. 14, 1945. Div. 8-502-M5 

50. Determinations of the Heats of Combustion of Explosives, 

George B. Kistiakowsky, OSRD 293, NDCrc-46, Service 
Project OD-01, Report 148, to Dec. 15, 1941, Harvard 
University, Dec. 29, 1941. Div. 8-203.2-Ml 

51. The Heats of Combustion of Explosives, George B. Kistia- 

kowsky, OSRD 702, NDCrc-46, Service Project OD-01, 
Report 288, to July 1, 1942, Harvard University, July 
15, 1942. Div. 8-203.2-M2 

52. Heat of Combustion of Explosive Substances, Gebhard 
Stegeman, OSRD 5306, OEMsr-754, Service Project OD- 
01, University of Pittsburgh, July 4, 1945. 

Div. 8-203.2-M5 


fCDX IQ DENTl A Ll 


162 


BIBLIOGRAPHY 


53. Color Tests for High Explosives, Ralph L. Shriner, OSRD 

5397, OEMsr-701, Service Project OD-01, Indiana Uni- 
versity, Aug. 4, 1945. Div. 8-110.4-M6 

54. Polar ographic Investigation of Nitro Compounds, James J. 
Lingane, OSRD 4564, OEMsr-1028, Service Project OD- 
118, Harvard University, Jan. 9, 1945. Div. 8-106-M6 

55. Microscopic Examination of High Explosives and Boosters, 
Alfred T. Blomquist, OSRD 3014, OEMsr-193, Service 
Project OD-109, Cornell L^niversity, Aug. 1, 1941. 

Div. 8-110.3-Ml 

56. Die Krystallanalyze, Lehmann, Wilhelm Engelmann, 
Leipzig, 1891. 

57. Thesis, W. C. IVIcCrone, Jr., Cornell Llniversity, 1942. 
58a. Cornpilation of Data on Organic Explosives, A. H. Blatt, 

OSRD 2014, OEMsr-741, Service Projects NO-BIO and 
OD-01, Queens College, Feb. 29, 1944. Div. 8-200-M2 
58b. OSRD 1085, A. H. Blatt and I>ank C. Whitmore, De- 
cember 1942. 

59. Surveillance Testing of High Explosives, Russell McGill, 

OSRD 1947, OEMsr-202, Service Projects OD-01 and 
OD-04, Report to July 15, 1943, Carnegie Institute of 
Technology, Oct. 23, 1943. Div. 8-201-M4 

60. Surveillance of High Explosives, Harold Salwin and F. H. 

Westheimer, OSRD 5596, OEMsr-202, Service Projects 
NO-231, OD-01, and NO-290, Carnegie Institute of 
Technology, Nov. 8, 1945. Div. 8-100-M2 


Chapter 3 

1. Shaped-Charge Boynhs, J. F. Lemons, E. J. Huber, and 

M. A. Paul, OSRD 5600, OEMsr-202, Service Project 
AN-1, ERL, Carnegie Institute of Technology, Dec. 20, 
1945. Div. 8-402-M8 

2. Point Initiating Fuzes for Shaped-Charge Weapons, J. F. 

Lemons and M. A. Paul, OSRD 5601, OEMsr-202, Serv- 
ice Project AN-1, ERL, Carnegie Institute of Tech- 
nology, Jan. 2, 1946. Div. 8-402-M9 

3. Studies of a Shaped-Charge Assisted Shaped Armor Pierc- 

ing Bomb, L. Paul Saxer, OSRD 5605, OEMsr-202, Serv- 
ice Project AN-1, ERL, Carnegie Institute of Tech- 
nology, Jan. 18, 1946. Div. 8-402-MlO 

4. Development of the Antisubmarine Shaped-Charge Scatter 

Bomb, OSRD 5760, OEMsr-764, Service Project AN-1, 
E. I. duPont de Nemours and Company, Inc., Oct. 1, 
1945. Div. 8-402-M2 

5. Controlled Fragmentation and Shaped Charges, compiled 
by George B. Kistiakowsky, Service Projects AN-1, 
NO-1 10 and NO-133, Interim Reports CF-1 through 
CF-12, covering period from Aug. 15, 1942 to Aug. 15, 

1943, September 1942 to August 1943. Div. 8-405-Ml 

6. Shaped Charges, compiled by George B. Kistiakowsky 

and H. J. Fisher, Service Project AN-1, Interim Report 
SC-1, covering period from Aug. 15 to Sept. 15, 1943, 
September 1943 to August 1945. Div. 8-402-Ml 

7. Shaped Charges, compiled by George B. Kistiakowsky 

and H. J. Fisher, Service Project AN-1, Interim Report 
SC-3, covering period from Oct. 15 to Nov. 15, 1943, 
September 1943 to August 1945. Div. 8-402-Ml 

8. Shaped Charges, compiled by George B. Kistiakowsky 
and H. J. Fisher, Service Project AN-1, Interim Report 
SC-5, covering period from Dec. 15, 1943 to Jan. 15, 

1944, September 1943 to August 1945. Div. 8-402-Ml 

9. Shaped Charges, compiled by George B. Kistiakowsky 

and H. J. Fisher, Service Project AN-1, Interim Report 
SC-6, covering period from Jan. 15 to Feb. 15, 1944, 
September 1943 to August 1945. Div. 8-402-Ml 


10. Shaped Charges, compiled by George B. Kistiakowsky 

and H. J. Fisher, Service Project AN-1, Interim Report 
SC-11, covering period from June 15 to July 15, 1944, 
September 1943 to August 1945. Div. 8-402-Ml 

11. Antisubmarine Shaped-Charge Follow-Through Bomb, 
OSRD 5753, OEMsr-764, Service Project AN-1, E. I. 
duPont de Nemours and Company, Inc., Oct. 22, 1945. 

Div. 8-402-M4 

12. Shaped Charges, compiled by George B. Kistiakowsky 
and H. J. Fisher, Service Project AN-1, Interim Report 
SC-4 through SC-24, covering period from Nov. 15, 1943 
to Aug. 15, 1945, September 1943 to August 1945. 

Div. 8-402-Ml 

13. Shaped-Charge Torpedo Warheads, OSRD 5752, OEMsr- 

764, Service Project AN-1, E. I. duPont de Nemours 
and Company, Inc., Oct. 9, 1945. Div. 8-402-M3 

14. Controlled Fragmentation and Shaped Charges, compiled 
by George B. Kistiakowsky, Service Projects AN-1, 
NO-1 10 and NO-133, Interim Reports CF-4 through 
CF-12, covering period from Nov. 15, 1942 to Aug. 15, 
1945, September 1942 to August 1943. Div. 8-405-Ml 

15. Shaped Charges, compiled by George B. Kistiakowsky 
and H. J. Fisher, Service Project AN-1, Interim Reports 
SC-1 through SC-24, covering period from Aug. 15, 1943 
to Aug. 15, 1945, September 1943 to August 1945. 

Div. 8-402-Ml 

16. Development of a Shaped-Charge Follow-Through Weapon, 

Morris Muskat, OSRD 6227, OEMsr-959, Service Project 
AN-1, Gulf Research and Development Company, Nov. 
20, 1945. Div. 8-402-M7 

17. Microwave Tube Destruction, D. P. MacDougall, OSRD 

1122, OEMsr-202, Service Project SC-41, Progress Re- 
port 460, to Dec. 1, 1942, Carnegie Institute of Tech- 
nology, Dec. 9, 1942. Div. 8-303-Ml 

18. Microwave Tube Destruction, M. A. Paul, OSRD 1287, 

OEMsr-202, Service Project SC-41, Progress Report to 
Mar. 10, 1943, ERL, Carnegie Institute of Technology, 

Mar. 23, 1943. Div. 8-303-M2 

19. Microwave Tube Destruction {Final Report), M. A. Paul, 
OSRD 1723, OEMsr-202, Service Project SC-41, ERL, 
Carnegie Institute of Technology, Aug. 20, 1943. 

Div. 8-303-M3 

20. Shaped-Charge Boosters, Leon Goodman, OSRD 5629, 
OEMsr-202, Service Project AN-1, ERL, Carnegie In- 
stitute of Technology, Dec. 26, 1945. Div. 8-704-Ml 

21. Detonation, Fragmentation and Air Blast, compiled by 
George B. Kistiakowsky and H. J. Fisher, Service Pro- 
jects OD-02, OD-03 and others. Interim Reports DFA-3 
through DFA-9, covering period from Oct. 15, 1943 to 
May 15, 1944, September 1943 to August 1945. 

Div. 8-500-M2 

22. Development of Linear Charges, Final Report on Mark 29 

Device, OSRD 3781, OEMsr-828, Service Project NS-125, 
E. I. duPont de Nemours and Company, Inc., June 15, 
1944. Div. 8-302-M3 

23. Mark 29 Device, D. P. MacDougall and W. E. Lawson, 

Service Projects NS-125, Interim Reports M29-1 through 
M29-9, covering period from Nov. 15, 1942 to Oct. 15, 
1943, Carnegie Institute of Technology and E. I. duPont 
de Nemours and Company, Inc., December 1942 to 
October 1943. Div. 8-302-Ml 

24. The Design of Explosive Streamers, J. H. Lum and J. K. 

Bragg, OSRD 1382, OEMsr-202, Service Project NS-125, 
Report to Apr. 15, 1943, Carnegie Institute of Tech- 
nology, May 5, 194k Div. 8-302-M2 

25. Liquid Explosives, OSRD 4815, OEMsr-828, Service Proj- 

ect CE-32, E. I. duPont de Nemours and Company, Inc., 
Mar. 31, 1945. Div. 8-304-M2 




BIBLIOGRAPHY 


163 


20. Development and Testing of Liquid Explosives for Mine 
Clearing, H. J. Fisher, OSRD 5749, ()E]Msr-202, Service 
Project CE-32, ERL, Carnegie Institute of Teclmology, 
Jan. 28, 1940. Div. 8-304-]\I5 

27. Increased Visibility of Antiaircraft Shell Bursts, D. P. 

MacDoiigall, OSRD 412, OEMsr-202, Service Project 
OD-31, Report 190, to Feb. 15, 1942, Carnegie Institute 
of Technology, Feb. 25, 1942. Div. 8-301-Ml 

28. Increased Visibility of Antiaircraft Shell Bursts, D. P. 

MacDougall, OSRD 559, OEMsr-202, Service Project 
OD-31, Serial 239, Carnegie Institute of Technology, 
May 8, 1942. Div. 8-301-M2 


Chapter 4 

1. The Flash Photography of Detonating Explosives, G. H. 
Messerly, OSRD 1488, OEMsr-202, Service Project OD- 
02, Progress Report to May 1, 1943, ERL, Carnegie In- 
stitute of Technology, June 3, 1943. Div. 8-401-M2 

2. The Application of Flash Photography to the Study of Ex- 
plosion Phenomena, Elizabeth M. Boggs, R. J. Brum- 
baugh, and G. H. Messerly, OSRD 5010, OEMsr-202, 
Service Projects OD-02 and XO-291, ERL, Carnegie In- 
stitute of Technologj', Jan. 28, 1940. Div. 8-401-M7 

3. A Rotating-Drum Camera for the Optical Study of Detona- 

tions, D. P. MacDougall, OSRD 082, OEMsr-202, Service 
Project OD-04, Serial 285, Carnegie Institute of Tech- 
nology, July 8, 1942. Div. 8-401-Ml 

4. Optical Studies of Strong Shock TErn’es, Elizabeth M. Boggs 

and M. D. Hurwitz, OSRD 5013, OEMsr-202, Service 
Projects OD-04 and NO-291, ERL, Carnegie Institute of 
Technology, Jan. 15, 1940. Div. 8-403-M2 

5. The Use of the Rotating-Drum Camera for the Measurement 

of the Velocities of Shell or Bomb Fragments, G. H. Messerly, 
OSRD 3900, OEMsr-202, Service Projects NO-1 10, NO- 
107 and OD-152, ERL, Carnegie Institute of Technology, 
July 15, 1944. Div. 8-401-M3 

0. Three-Station Fragment Retardation A pparatus at Bruceton;*' 
R. W. Drake, OSRD 5019, OEMsr-202, Service Projects 
NO-1 10, NO-107 and OD-152, PRIL, Carnegie Institute of 
Technology, Dec. 3, 1945. Div. 8-405-Mll 

7. Studies of Shell-Fragment Mass Distribution; Part II, The 
Mark 29-2 S" 150 AP Projectile with Explosive D and with 
Composition A-3, M. A. Paul and \V. K. Hall, OSRD 5000, 
OEMsr-202, Service Projects NO-1 10, NO-107 and OD- 
152, ERL, Carnegie Institute of Technology, Jan. 28, 1940. 

Div. 8-405-M18 

8. Studies of Shell-Fragment Mass Distribution; Part I, Navy 
3" 150 Antiaircraft Projectiles, Mark 27-3 and Mark 31-i, 
M. A. Paul and W. K. Hall, OSRD 5007, OEMsr-202, 
Service Projects NO-107 and OD-152, ERL, Carnegie In- 
stitute of Technology, Jan. 5, 1940. Div. 8-405-M15 

9. Studies of Shell-Fragment Mass Distribution; Part III, 
Effect of Booster Size in the Mark 27-3 3” 150 Antiaircraft 
Projectile Loaded with Cast TNT, M. A. Paul and W. K. 

■ Hall, OSRD 5008, OEMsr-202, Service Projects NO-167 
and NO-138, ERL, Carnegie Institute of Technology 
Jan. 22, 1946. Div. 8-405-M17 

10. Dependence of Fragment Velocity and Fragment Penetration 

on Charge-Weight Ratio of Shells, R. W. Drake, OSRD 
5621, OEMsr-202, Service Projects NO-1 10, NO-167 and 
OD-152, ERL, Carnegie Institute of Technology, Dec. 21, 
1945. Div. 8-405-M13 

11. Controlled Fragmentation of Thin-Cased Munitions, Eugene 

H. Eyster, OSRD 5630, OEMsr-202, Service Projects NO- 
110, NO-167, and OD-152, ERL, Carnegie Institute of 
Technology, Jan. 15, 1946. Div. 8-405-M16 


12. Detonation, Fragmentation and Air Blast, compiled l)y 

George B. Kistiakowsky and H. J. Fisher, Service Projects, 
OD-02, OD-03 and others. Interim Report DFA-15, cover- 
ing period from Oct. 15, 1944 to Mar. 15, 1945, September 
1943 to August 1945. Div. 8-500-M2 

13. Fragment Velocity and Panel Penetration of Several Ex- 
plosives in Simulated Shells, R. W. Drake, OSRD 5622 
OEMsr-202, Service Projects NO-167 and OD-152, ERL, 
Carnegie Institute of Technology, Jan. 2, 1946. 

Div. 8-405-M14 

14. Fundamental Study of Panel Penetration, R. W. Drake, 

OSRD 5623, OEMsr-202, Service Projects OD-152, NO- 
110, and NO-167, ERL, Carnegie Institute of Technology, 
Nov. 9, 1945. Div. 8-404-M4 

15. Fragment Velocity and Panel Penetration, A Comparison of 

Haleite and Ednatol ivith Service Filling; Part I, The 37-mm 
M-63 3" M- 42 A 1 and 90-mm M-71 Projectiles, R. W. 
Drake, OSRD 1964, OEMsr-202, Service Projects OD-152 
and NO-1 10, ERL, Carnegie Institute of Technology, 
Oct. 30, 1943. Div. 8-405-M2 

16. Fragment Velocity and Panel Penetration, A Comparison of 
Heleite and Ednatol with Service Filling; Part II, The 40 -mm 
Mark II T/L Projectiles, R. W. Drake, OSRD 1965, 
OEMsr-202, Service Projects OD-152 and NO-1 10, ERL, 
Carnegie Institute of Technology, Oct. 30, 1943. 

Div. 8-405-M3 

17. Fragment Velocity and Panel Penetration, A Comparison of 
Haleite and Ednatol with Service Filling; Part III, The 
90-mm M-71E2 Projectiles, R. W. Drake, OSRD 2071, 
OEMsr-202, Service Projects OD-152 and NO-1 10, ERL, 
Carnegie Institute of Technology, Nov. 29, 1943. 

Div. 8-405-M4 

18. Fragment Velocity and Panel Penetration, A Comparison of 
Haleite and Ednatol with Service Filling; Part IV. The 75- 
mm M-Jj-S and M-48E2 Projectiles, R. W. Drake, OSRD 
3022, OEMsr-202, Service Projects OD-152 and NO-1 10, 
ERL, Carnegie Institute of Technology, Dec. 18, 1943. 

Div. 8-405-M5 

19. Fragment Velocity and Panel Penetration, A Comparison of 

Haleite and Ednatol with Service Filling; Part V, the 
M-49A2 60-mm Mortar Shell; Part VI, the M-54 37-mm 
Projectile, R. W. Drake, OSRD 3079, OEMsr-202, Service 
Projects OD-152 and NO-1 10, ERL, Carnegie Institute of 
Technology, Jan. 3, 1944. Div. 8-405-M6 

20. Fragment Velocity and Fragmentation of 3" 150 Mark 29 
Model 3 AP Shell, Loaded with Composition A-3 and Ex- 
plosive D, R. W. Drake, OSRD 5213, OEMsr-202, Service 
Projects NO-1 10, NO-167 and OD-152, ERL, Carnegie 
Institute of Technology, June 15, 1945. Div. 8-405-M7 

21. Fragment Velocity and Fragmentation 3" 150 Mark 27 

Model 3 Antiaircraft Shell Loaded with Composition A-3 
and with TNT and Cavitized for Mark 58 Fuze, R. W, 
Drake, OSRD 5266, OEMsr-202, Service Projects NO-1 10, 
NO-167, and OD-152, ERL, Carnegie Institute of Tech- 
nology, June 26, 1945. Div. 8-405-M8 

22. Fragment Velocity and Fragmmdation of 3" f 50 EX-2 

{Mark 27, Model 3) Antiaircraft Shell Loaded with TNT 
and with Composition A-3 and Cavitized for Mark 45 Fuze, 
R. W. Drake, OSRD 5267, OEMsr-202, Service Projects 
NO-1 10, NO-167, and OD-152, ERL, Carnegie Instutute 
of Technology, June 27, 1945. Div. 8-301-M3 

23. Fragment Velocity and Fragmentation of 3" {50 {Mark 27, 

Model 3) Antiaricraft Shell Loaded with TNT and with 
Composition A-3 and Cavitized for Mark 54 Aux. Det., 
R. W. Drake, OSRD 5531, OEMsr-202, Service Projects 
NO-1 10, NO-167, and OD-152, ERL, Carnegie Institute 
of Technology, Sept. 4, 1945. Div. 8-30 1-M 4 


^.M-'1DENT1AL) 


164 


BIBLIOGRAPHY 


24. Fragment Velocity atid Panel Penetration with M-17 90- nun 
Shell TNT Loaded, Fuze Fragments, Base Fragments and 
Nose-Wall Fragments, K. Drake, OSRD 5571, OEMsr- 
202, Service Projects NO-1 10, NO-167, and OD-152, ERL, 
Carnegie Institute of Technologv, Oct. 3, 1945. 

Div. 8-405-M9 

25. Fragment Velocity and Panel Penetration, Data Obtained for 

Army Ordnance Development Project TA-PA'E-Dl, A Com- 
paiison of Haleite and Ednatol with Service Filling, R. W. 
Drake, OSRD 5572, OEMsr-202, Service Projects NO-1 10, 
NO-167, and OD-152, ERL, Carnegie Institute of Tech- 
nology, Oct. 3, 1945. Div. 8-405-M10 

26. Panel Fragmentation Trials of Various 81-mm M ortar Shells, 

R. W. Drake, OSRD 5620, OEAIsr-202, Service Project 
OD-152, ERL, Carnegie Institute of Technologv, Dec. 3, 
1945. Div. ^405-M12 

27. Survey of the History and Uses of the Hollow Charge Effect 
up to 1941, British Report, A.C. 1312. 

28. Cavity Effect of High Explosives, A Summary of Recent 
Work on Hollow Charges and Their Service Applications, 
A.C. 4026, ARD Explosives Report 28/43, British Report. 

29. A Review of Certain Aspects of Research on M unroe Jets, 
D. C. Pack, ARD Theoretical Research Survey 1/44, 
British Report [1943]. 

30. Shaped-Charge Research Review, The Main Lines of Basic 
Research on Hollow Charges, ARD Explosives Report 
669/44, British Report [covering period from August 1943 
to August 1944]. 

31. Joint Report on Research and Development Work on Hollow 
Charges, HCP Report 89, ARD, ADD Interdepartmental 
Panel on Hollow Charge Projectiles, British Report. 
(This report includes reference 30.) 

32. The Effects of Vaiious Aberrations on the Performances of 
Cavity Charges, M. A. Paul, E. P. Meibohm and H. L. 
Bachrach, OSRD 5599, OEMsr-202, Service Project AN-1, 
ERL, Carnegie Institute of Technology, Dec. 3, 1945. 

Div. 8-406-M8 

33. Steel Target Penetration in Air by Small Scale Cavity 
Charges, E. J. Huber, J. F. Lemons and M. A. Paul, OSRD 
5604, OEIMsr-202, Service Project AN-1, ERL, Carnegie 
Institute of Technology, Jan. 15, 1946. Div. 8-406-M9 

34. Penetration of Steel Targets in Air by Small Scale Cavity 

Charges, M. A. Paul, OSRD 1861, OEMsr-202, Service 
Project AN-1, ERL, Carnegie Institute of Technology, 
Sept. 29, 1943. Div. 8-406-M4 

35. The Mechanism of Jet Formation on Scale Laws for Linings 
to M unroe Charges; Part I Fluid Linings, T. Nash and 
A. R. Ubbelohde, A.C. 6366, British Report. 

36. Point Inititating Fuzes for Shaped-Charge Weapons, J. F. 

Lemons and M. A, Paul, Service Project AN-1, ERL, 
OSRD 5601, OEMsr-202, Carnegie Institute of Technol- 
ogy, Jan. 18, 1946. Div. 8-402-M9 

37 . L^npublished Results [of the work] of Major J. C. Clark 
at the Ballistic Research Laboratory. 

38. Shaped Charges for Perforation of Concrete, Eastern Lab- 
oratory Report, E. 1. duPont de Nemours and Company, 
Inc., May 24, 1943. 

39. Fundamental Investigation of Glass Cones for Use in Caiity 
Charges, Army Ordnance Department Contract W-670- 
ORD-4331, Eastern Laboratory, E. 1. duPont de Nemours 
and Company, Inc. 

40. Improvement of Head of Rocket HEAT 2.36 (Final Report), 
Army Ordnance Department Contract W-670-ORD-4331, 
Eastern Laboratory, E. 1. duPont de Nemours and Com- 
pany, Inc. 

41. Army Ordnance Department Contract W-670-ORD- 
4331, Eastern Laboratory Report, E. 1. duPont de Ne- 
mours and Company, Inc., March 1943. 


42. The Mechatiism of Jet Formation in the Munroe Effect, 
W. IM. Evans and A. R. Ubbelohde, British Rei)ort A.C. 
1591. 

43. The Comparative Properties of Miuiroe Jets Formed by 
VaHous Lined Hollow Charges, W. M. Evans, and A. R. 
Ubbelohde, British Report, A.C. 2461. 

44. Investigation of 30-lb, 35-lb, and 45-lb Shaped Charges for 
Concrete Demolition, Eastern Laboratory Report, E. I. 
duPont de Nemours and Company, Inc., July 31, 1943. 

45. 40-lb Shaped Demolition Charge M3, Army Ordnance De- 
partment Contract W-670-ORD-4331, Eastern Laboratory 
Report, E. 1. duPont de Nemours and Company, Inc., 
Aug. 28, 1945. 

46. Theory and Application of the Canty Effect, Army Ord- 
nance Department Contract W-670-ORD-4331, Eastern 
Laboratory Report, E. I. duPont de Nemours and Com- 
ixany, Inc., November 1943. 

47. Development of Shaped Charge M2A3, Army Ordnance De- 
j)artment Contract \V-670-ORD-4331, Eastern Labora- 
tory Report, E. 1. duPont de Nemours and Coinj^any, Inc., 
¥eh. 23, 1945. 

48. Symposiiun on Shaped Charges; Sectioning of Explosive- 
Filled Ordnance by Means of Cavity Charges, H. W. Kline, 
OSRD 5754, OEMsr-950, Division 2 and 8 Armor and 
Ordnance Report A-346, Carnegie Institute of Technology, 
May 9, 1945. 

49. Shaped-Charge Bombs, J. F. Lemons, E. J. Huber, and 

M. A. Paul, OSRD 5600, OEMsr-202, Service Project 
AN-1, ERL, Carnegie Institute of Technology, Dec. 20, 
1945. Div. 8-402-M8 

50. The Effect of U nsymmetrical Cone Alignment on the Jet 

from a Cavity Charge, IM. A. Paul, OSRD 1681, OEMsr- 
202, Service Project AN-1, ERL, Carnegie Institute of 
Technology, Aug. 5, 1943. Div. 8-406-M2 

51. Radiography of Explosive Materials, O. E. A. Bolduan, 

OSRD 5575, OEMsr-202, Service Projects OD-01 and 
NO-290, ERL, Carnegie Institute of Technology, Nov. 5, 
1945. Div. 8-400-M4 

52. Hollow Charge Rotated Projectiles, by M. D. 1, British Re- 

port, A.C. 3987. 

53. Target Penetration by the Jet from a Rotating Cone Charge, 
M. A. Paul, OSRD 1680, OEMsr-202, Service Project 
AN-1, ERL, Carnegie Institute of Technology, Aug. 5, 

1943. Div. 8-404-M2 

54. Target Penetration by the Jet from a Rotating Cone Charge, 
M. A. Paul, OSRD 3874, OEMsr-202, Service Project 
AN-1, ERL, Carnegie Institute of Technology, July 10, 

1944. Div. 8-404-M3 

55. Symposium on Shaped Charges; Flash Radiographs of Ro- 

tating Cavity Charges, J. C. Clark, OSRD 5754, OEMsr- 
950, Divisions 2 and 8 Armor and Ordnance Report A-346, 
Carnegie Institute of Technology, May 9, 1945. 

56. (Memorandum Report), J. C. Clark and C. E. Hawk 
Project 4509, Ballistic Research Laboratory, Aberdeen 
Proving Ground, Apr. 12, 1945. 

57. Target Penetration by Rotating Cavity Charges, M. A. Paul, 
OSRD 5598, OEMsr-202, Service Project AN-1, ERL, 
Carnegie Institute of Technology, Nov. 5, 1945. 

Div. 8-406-M7 

58. Penetration of Steel Targets by Linear Charges, M. A. Paul, 

OSRD 1383, OEMsr-202, Service Project AN-1, Progress 
Report to Apr. 1, 1943, ERL, Carnegie Institute of Tech- 
nology, May 4, 1943. Div. 8-404-Ml 

59. Shaped Charges, compiled by George B. Kistiakowsky 

and H. J. Fisher, Service Project AN-1, Interim Report 
SC-5, covering period from Dec. 15, 1943 to Jan. 15, 1944, 
September 1943 to August 1945. Div. 8-402-Ml 


CnxFuijNxrAil- 


BIBLIOGRAPHY 


165 


GO. .1 Report on the Application of Shaped Charges, Explosives 
Investigation Laboratory, Naval Powder Factory, Indian 
Head, Md. 

61. Undenvater Penetration by Small Scale Shaped Charges, 

E. P. Meibohm and M. A. Paul, OSRD 5569, OElVIsr-202, 
Service Project AN-1, ERL, Carnegie Institute of Tech- 
nology, Oct. 24, 1945. Div. 8-402-M6 

62. Scaling Laws for Underwater Penetration with Cavity 

Charges, OSRD 5392, OEiMsr-764, Service Project AN-1, 
E. I. diiPont de Nemours and Company, Inc., Aug. 1, 
1945. Div. 8-406-1M6 

63. Shaped-Charge Torpedo Warheads, OSRD 5752, OEMsr- 

764, Service Project AN-1, E. I. duPont de Nemours and 
Company, Inc., Oct. 9, 1945. Div. 8-402-1M3 

64. High Speed Radiographic Studies of the Controlled Frag- 
mentation; I, The Collapse of Steel Cavity Charge Liners, 

L. B. Seely and J. C. Clark, Report 368, Ballistic Research 
Laboratory. 

65. Studies of Shaped Charges by Flash Radiography; II, The 
Munroe Effect, J. L. Tuck (M.D.l.) and ARD, British 
Report, A. C. 4130. 

66. High Speed Radiographic Studies of Controlled Fragmenia- 
tion; III, The Collapse of Hemisphencal and H eniicylindri- 
cal Steel Cavity Charge Liners, L. B. Seely and J. C. Clark, 
Report 415, Ballistic Research Laboratory. 

67. Flash Radiography of Shaped Charges, The Collapse of 
Hemispherical and Dish-Shaped Liners, by ARD, ARD 
Met. Report 62/45, ARD, British Report, A.C. 8480. 

68. The Flash Photography of Detonating Explosives, G. H. 

Messerly, OSRD 1488, OEMsr-202, Service Project OD- 
02, Progress Report to May 1, 1943, ERL, Carnegie In- 
stitute of Technology, June 3, 1943. Div. 8-401-M2 

69. Studies of Shaped Charges with the Rotating-Drum Camera, 

M. D. Hur^^^tz, and H. A. Strecker, OSRD 5615, OEMsr- 

202, Service Project AN-1, ERL, Carnegie Institute of 
Technology, Jan. 15, 1946. Div. 8-401-M5 

70. Mathenmtical Jet Theory of Lined Hollow Charges, Garrett 
Birkhoff, Report 370, Ballistic Research Laboratory. 

71. A Note on the Theory of the Munroe Effect, J. L. Tuck, 
British Report, A.C. 3596. 

72. A Formulation of Mr. Tuck’s Conception of Munroe Jets, 

G. I. Taylor, British Report A.C. 3734. 

73. Expenmental Studies of Cone Collapse and Jet Formation; 
Part I, Recovery of Cones from Low-Powered Charges, 

H. Linschitz and M. A. Paul, OSRD 2070, OEMsr-202, 

Service Project AN-1, ERL, Carnegie Institute of Tech- 
nology, Nov. 29, 1943. Div. 8-400-M2 

74. Experimental Studies of Cone Collapse and Jet Formation; 

Part II, The Mass Contributed to the Jet, M. A. Paul and 
H. Linschitz, OSRD 2072, OEMsr-202, Service Project 
AN-1, ERL, Carnegie Institute of Technology, Nov. 29, 
1943. Div. 8-400-M3 

75. Experimental Studies of Cone Collapse and Jet Formation; 

Part III, Further Studies of Jet Mass Origin and Slug 
Structure, M. A. Paul, OSRD 5602, OEMsr-202, Service 
Project AN-1, ERL, Carnegie Institute of Technology, 
Dec. 20, 1945. Div. 8-400-M5 

76. “Effects of High Hydrostatic Pressure on the Plastic Prop- 
erties of Metals,” P. W. Bridgman, Reviews of Modern 
Physics, Vol. 17, 1945, p. 3. 

77. Final Report on the Plastic Properties of Steel under Large 
Strains and High Stresses, P. W. Bridgman, OSRD 4256, 
OEMsr-201, Service Project NO-11, Report A-294, 
Harvard University, October 1944. Div. 2-431.1 1-M6 

78. Velocity Gradient in Shaped Charges with Conical Liners, 
M. R. Jefferis, British Report A.C. 8435. 


79. The Mechanism of Action of Canty Charges, George B. 

Kistiakowsky, D. P. MacDougall and G. H, Messerly, 
OSRD 1338, OEMsr-202, Service Project AN-1, Progress 
Report to Mar. 15, 1943, ERL, Carnegie Institute of 
Technology, Apr. 12, 1943. Div. 8-406-Ml 

80. Controlled Fragmentation and Shaped Charges, compiled by 
George B. Kistiakowsky, Service Projects AN-1, NO-1 10, 
and NO-133, Interim Report CF-9 covering period from 
Apr. 15 to May 15, 1943, September 1942 to August 1943. 

Div. 8-405-Ml 

81. The Effective Diameter of the Jet from a Cavity Charge, 

M. A. Paul, OSRD 1679, OEMsr-202, Service Project 
AN-1, ERL, Carnegie Institute of Technology, Aug. 5, 
1943. Div. 8-406-M3 

82. Motnentum and Kinetic Energy of the Shaped-Charge Jel, 

]\I. A. Paul and J. F. Lemons, OSRD 5570, OEMsr-202, 
Service Project AN-1, ERL, Carnegie Institute of Tech- 
nology, Oct. 23, 1945. Div. 8-402-M5 

83. Suggestions for Improvement for C. S. Bombs of the Disc 
Type, H. J. Poole, British Report A.C. 2644. 

84. Improvements in the Performance of Cavity Charges, J. A. 

Paul and J. F. Lemons, OSRD 3443, OEMsr-202, Service 
Project AN-1, ERL, Carnegie Institute of Technology, 
Apr. 3, 1944. Div. 8-406-M5 

85. Shaped Detonation TFav'cs, S. J. Jacobs and Robert J. 

Grabenstetter, OSRD 5603, OEMsr-202, Service Project 
AN-1, ERL, Carnegie Institute of Technology, Jan. 28, 
1946. Div. 8-402-Mll 

86. The Interaction of Shock Waves, R. W. Wood, OSRD 1996, 
OEMsr-773, Service Projects AN-1 and OD-03, The 
Johns Hopkins University, Nov. 4, 1943. Div. 2-120-M4 

87. Point-Initiating Base-Detonating Electromagnetic Fuze, 

T2003, F. T. McClure, D. D. Miller, J. F. Lemons, and 
M. A. Paul, OSRD 5881, OEMsr-273, NDRC Division 3 
and Division 8 Report Series W and Nmnber 6.1, BTL, 
ERL, and Alleghany Ballistics Laboratory, George Wash- 
ington LT^niversity, March 1946. Div. 3-430-M6 


Chapter 5 

1. Gottinger N achrichten, Bernard Riemann, Vol. 8, 1860, 
p. 156. 

2. Proceedings of the Royal Society of London, Rankine, 
Ser. A, Vol. , 160, 1870, p. 277. 

3. Journal de I’Ecole Poly technique, Paris, Hugoniot, Vol. 57, 
1887, p. 3; Vol. 58, 1888, p. 1. 

4. “On the Rate of Explosion in Gases,” D. L. Chapman, 
The London, Edinburgh and Dublin Philosophical Maga- 
zine and Journal of Sciences, Ser. 5, Vol. 47, January 1899, 
pp. 90-104. 

5. Comptes Reridus, M. Jonget, Vol. 132, 1901, p. 673; “Sur 
la Propagation des Reactions Chimique dans les Gaz,” 
M. Jouget, Journal de Mathematique, 1905, pp. 347-425; 
1906, pp. 5-86; 

Mechanique des Explosifs, Emile Jouget, O. Doin et Fils, 
Paris, 1917. 

6. “Stosswelle und Detonation,” R, Becker, Zeitschrift fiir 
Physik, Vol. 8, 1922, pp. 321-362; 

“Impact Waves and Detonation” (Parts I and II), 
National Advisory Committee for Aeronautics, Technical 
Memoranda 505 and 506. 

7. “On the Thermodynamic Theory of Detonation,” R. L. 
Scorah, Journal of Chemical Physics, Vol. 3, 1935, pp. 425- 
430. 

8. “Explosions in Detonating Gas Mixtures. Part I, Cal- 
culation of Rates of Explosions in Mixtures of Hydrogen 
and Oxygen and the Influence of Rare Gases,” B. Lewis 


fcONPIDENTiriT^ 


166 


BIBLIOGRAPHY 


and J. H. Friaiif, Journal of the American Chemical Society, 
Vol. 52, 1930, pp. 3905-3920. 

9. Zeitschrift fiir das Gesamie Schiess- imd Sprengstoffwesen, 
Schmidt, Vol. 30, 1935, p. 364; Vol. 31, 1936,' pp. 8, 37, 
80, 114, 149, 183, 218, 248, 284, 322. 

10. The Prediction of Detonation Velocities of Solid Explosives, 

George B. Kistiakowsky and E. Bright Wilson, Jr., OSRD 
69, NDCrc-168, Service Project OD-02, Serial 6, Harvard 
University, Jan. 17, 1941. Div. 8-501-Ml 

11. The Hydrodynamic Theory of Detonation and Shock Waves, 
George B. Kistiakowsky and E. Bright Wilson, Jr., OSRD 
114, NDCrc-30, Service Projects OD-02 and OD-03, 
Final Report 52, Harvard University, Aug. 15, 1941. 

Div. 2-131-Ml 

12. Plane Shock Waxes, George B. Kistiakowsky and E. Bright 
Wilson, Jr., OSRD 70, Service Projects OD-02 and OD-03, 
Progress Report 7, Harvard University, Jan. 17, 1941. 

Div. 2-r20-Ml 

13. Proceedings of the Royal Society of London, Lord Rayleigh, 
Ser. A, Vol. 84, 1910^ p. 247. 

14. Deviations from Thermal Equilibrium in Shock IFaccs, 
Bethe and Teller Report, NDRC. 

15. Tables of the Properties of Air along H ugoniot and the Adia- 

batics Terminating in the Hugoniot Curve, Stuart R. 
Brinkley, Jr., John G. Kirkwood, and John M. Richardson, 
OSRD 3550, Service Projects OD-03, NO-144, and NO-224, 
Cornell University, Apr. 27, 1944. Div. 2-120-M5 

16. Revised Method of Predicting the Detonation Velocities in 

Solid Explosives, Stuart R. Brinkley, Jr. and E. Bright 
Wilson, Jr., OSRD 905, NDCrc-168, Service Project 
OD-02, Report 374 to Sept. 12, 1942, Harvard University, 
Sept. 28, 1942. Div. 8-501-M2 

17. Thermochemistry and the Equation of State of the Propellant 
Gases, J. O. Hirschfelder, F. T. McClure, and C. F. 
Curtiss, OSRD 547, OEMsr-51, Division 1 Report A-48, 
Carnegie Institute of Washington, Apr. 22, 1942. 
Progress Report A-116, An extension and revision of 
NDRC Report A-48, Nov. 25, 1942. Div. 1-210.2-M3 

18. Calculation of the Detonation Velocities of Some Pure Ex- 
plosive, Stuart R. Brinkley, Jr. and E. Bright Wilson, Jr., 
OSRD 1707, NDCrc-168, Service Projects OD-02 and NO- 
144, Harvard University, Aug. 12, 1943. Div. 8-501-M4 

19. Letter to Stuart R. Brinkley, Jr. (unpublished), E. M. Boggs 
and F. J. Martin, ERL, November 1943. 

20. Calculation of Detonation Pressures of Several Explosives, 

Stuart R. Brinkley, Jr. and E. Bright Wilson, Jr., OSRD 
1231, NDCrc-168, Service Projects OD-02 and NO-144, 
Harvard University, Mar. 1, 1943. Div. 8-500-Ml 

21. Calculation of the Detonation Properties of Some Service 

Explosives, Stuart R. Brinkley, Jr. and E. Bright Wilson, 
Jr., OSRD 1510, NDCrc-168, Service Projects OD-02 and 
NO-144, Progress Report to June 1, 1943, Harvard Uni- 
versity, June 14, 1943. Div. 8-502-M2 

22. Theory of Detonation Waves, John von Neumann, OSRD 

549, OEMsr-218, Service Project OD-02, Progress Report 
238, to Apr. 1, 1942, Institute for Advanced Study, May 4, 
1942. Div. 8-502-Ml 

23. The Theory of Explosion Initiation, Ransom B. Parlin, 

George H. Duffy, R. E. Powell, and H. Eyring, OSRD 

2026, OEMsr-957, Service Project OD-02, Princeton Uni- 
versity, Nov. 13, 1943. Div. 8-502-M3 

24. I' he Chemical Reaction in a Detonation Wave, Henry Eyr- 
ing, Richard E. Powell, George H. Duffy, and Ransom B. 
Parlin, OSRD 3796, OEMsr-957, Service Projects NO-224 
and OD-02, Princeton University, June 17, 1944. 

Div. 8-502-M4 


CIia[»li*r 6 

1. Rocket Propellants, comi)ilcd by George B. Kistiakowsky 
and H. J. Fisher, Service Projects OD-14, NO-99, and 
others. Interim Report RP-25, covering period from Aug. 
15 to Sept. 15, 1944, September 1942 to August 1945, p. 17. 

Div. 8-607.5-M2 

2. Rocket Propellants, compiled by George B. Kistiakowsky 

and H. J, Fisher, Service Projects OD-14, NO-99, NO-151, 
and others. Interim Report RP-26, covering period from 
Sept. 15 to Oct. 15, 1944, September 1942 to August 1945, 
p. 17. Div. 8-607.5-M2 

3. Rocket Propellants, compiled by George B. Kistiakowsky 

and H. J. Fisher, Service Projects OD-14, NO-99, NO-151, 
and others. Interim Report RP-27, covering period from 
Oct. 15 to Nov. 15, 1944, September 1942 to August 1945, 
p. 15. Div. 8-607.5-M2 

4. Rocket Propellants, compiled by George B. Kistiakowsky 

and H. J. Fisher, Service Projects OD-14, NO-99, NO-151, 
and others. Interim Report RP-28, covering period from 
Nov. 15 to Dec. 15, 1944, September 1942 to August 1945, 
p. 18. Div. 8-607.5-1M2 

5. Rocket Propellants, compiled by George B. Kistiakowsky 

and H. J. Fisher, Service Projects OD-14, NO-99, NO-151, 
and others. Interim Report RP-29, covering period from 
Dec. 15, 1944 to Jan. 15, 1945, September 1942 to August 
1945, p. 36. Div. 8-607.5-M2 

6. Rocket Propellants, comjiiled by George B. Kistiakowsky 

and H. J. Fisher, Service Projects OD-14, NO-99, NO-151, 
and others. Interim Report RP-34, covering period from 
May 15 to June 15, 1945, September 1942 to August 1945, 
p. 58. Div. 8-607.5-M2 

7. The Theory of the Burning of Double-Base Rocket Powders, 
Oscar K. Rice, OSRD 5224, OEMsr-976, Service Project 
OD-14, LTniversity of North Carolina, June 25, 1945. 

Div. 8-601-M5 

8. The Theory of the Burning of Rocket Powders, Oscar K. 
Rice, OSRD 5574, OEMsr-976, Service Project OD-14, 
LTniversity of North Carolina, Nov. 1, 1945. 

Div. 8-601-M6 

9. Boys and Corner, British Report, A.C. 1139, Aug. 22, 1941. 
10a. Studies on Propellants, Bryce L. Crawford, Jr., Clayton 

M. Huggett, and R. G. Parr, Appendix to OSRD 6374, 
OEMsr-716, Service Projects OD-14 and NO-33, Division 
3 Interim Report LTM/21, University of Minnesota, 
Oct. 26, 1945. Div. 3-300-Ml 

10b. Studies on Propellants, Bryce L. Crawford, Jr., Clayton 
M. Huggett, and John J. McBrady, Appendix to OSRD 
6374, OEMsr-716, Service Projects OD-14 and NO-33, 
Division 3 Interim Report UM/37, University of Minne- 
sota, Aug. 15, 1945. Div. 3-300-Ml 

10c. Studies on Propellants, Bryce L. Crawford, Jr., Clayton 
M. Huggett, and John J. McBrady, Appendix to OSRD 
6374, OEMsr-716, Service Projects OD-14 and NO-33, 
Division 3 Interim Report UM/18, University of Minne- 
sota, Aug. 17, 1944. Div. 3-300-Ml 

lOd. Studies on Propellants, Clayton M. Huggett, Appendix to 
OSRD 6374, OEMsr-716, Service Projects OD-14 and 
NO-33, Division 3 Interim Report UM/34, University of 
Minnesota, June 26, 1945. Div. 3-300-Ml 

lOe. Studies on Propellants, Bryce L. Crawford, Jr., and R. G. 
Parr, Appendix to OSRD 6374, OEMsr-716, Service Proj- 
ects OD-14 and NO-33, Division 3 Interim Report UM/ 
29, LTniversity of Minnesota, Feb. 17, 1945. 

Div. 3-300-Ml 

lOf. Studies on Propellants, R. G. Parr and Bryce L. Craw- 
ford, Jr., Api)endix to OSRD 6374, OEMsr-716, Service 


UXFIJJgNTlAl] 


BIBLIOGRAPHY 


167 


Projects OD-14 and NO-33, Division 3 Interim Report 
UM/36, Lmiversity of Minnesota, July 11, 1945. 

Div. 3-300-Ml 

lOg. Studies on Propellants, R. G. Parr, Appendix to OSRD 
6374, OE]Msr-716, Service Projects OD-14 and NO-33, 
Division 3 Interim Report UM/38, University of Minne- 
sota, July 19, 1945. Div. 3-300-Ml 

lOh. Studies on Propellants, IM. T. Hanson, Appendix to OSRD 
6374, OEMsr-716, Service Projects Or)-14 and NO-33, 
Division 3 Interim Report UM/30, University of Minne- 
sota, Apr. 6, 1945. Div. 3-300-Ml 

lOi. Studies on Propellants, Bryce L. Cravdord, Jr., Clayton 
M. Huggett, M. T. Hanson, and John J. McBrady, Ap- 
pendix to OSRD 6374, OEMsr-716, Service Projects OD- 
14 and NO-33, Division 3 Interim Report UM/35, Uni- 
versity of Minnesota, July 20, 1945. Div. 3-300-Ml 

11. Memorandum to R. E. Gibson, A. E. Comley and Bryce L. 
Cravdord, Jr., July 3, 1943. 

12. The Mechanism of Powder Burning, F. Daniels, OSRD 
3206, OEMsr-762, Service Projects OD-26, OD-14, and 
CWS-22, Navy Project NO-33, Division 3 Armor and 
Ordnance Report A-243, University of Wisconsin, Jan. 20, 

1944. Div. 3-361.21-M2 

13. H. Eyring, R. Powell, G. Duffey, and R. B. Parlin, Prince- 
ton University, Apr. 20, 1945. 

14. Rocket Propellants, compiled by George B. Kistiakowsky 

and H. J. Fisher, Service Projects OD-14, NO-99, NO-151, 
and others. Interim Report RP-32, covering period from 
Mar. 15 to Apr. 15, 1945, September 1942 to August 1945, 
p. 56. Div. 8-607.5-M2 

15. Minutes of the Second Meeting of the Rocket Propellant 
Panel, J. H. Frazer, Allegany Ballistics Laboratory, 
Mar. 1, 1944, p. 10. 

16. Private Communication, Clayton M. Huggett. 

17. Survey of Investigations on New Propellants for Rockets and 
Other Jet-Propulsion Devices, Louis P. Hammett, OSRD 
5463, OEMsr-202, Service Projects AC-75, NA-197, and 
others, ERL, Carnegie Institute of Technology, Aug. 18, 

1945. Div. 8-603-M10 

18. Development of Plastic Propellants, F. P. Price, OSRD 
5581, OEMsr-202, Service Project OD-14, ERL, Carnegie 
Institute of Technology, Oct. 30, 1945. Div. 8-607. 1-M2 

19. The Present Status of Composite Propellant 218, Louis P. 
Hammett, OSRD 1177, OEMsr-194, OEMsr-639, and 
OEMsr-202, Service Project OD-14, Progress Report to 
Dec. 30, 1942, Monsanto Chemical Company and Carnegie 
Institute of Technology, Feb. 3, 1943. Div. 8-603-Ml 

20. Ballistic Properties of Composite Propellants 404 and 492, 

R. W. Broge, OSRD 5043, OEMsr-202, Service Projects 
AC-75 and OD-14, ERL, Carnegie Institute of Technology, 
May 9, 1945. Div. 8-603-M9 

21. General Properties of Molded Composite Propellants, F. A. 

Long, OSRD 5700, OEMsr-639, Service Projects AC-75, 
OD-14, and OD-i98, Monsanto Chemical Company, 
Nov. 8, 1945. Div. 8-603. 1-M5 

22. Rocket Fundamentals, OSRD 3992, OEMsr-273, Division 3 
Report ABL/SR-4, Allegany Ballistics Laboratory, George 
Washington University, Dec. 26, 1944. Div. 3-210-M3 

23. Cementing Technique for Fabricating Charges of Molded 
Composite Propellant, W. K. McEwen, OSRD 5587, 
OEMsr-202 and OEMsr-639, Service Projects AC-75 and 
OD-198, ERL, Carnegie Institute of Technology and 
Monsanto Chemical Company, Dec. 4, 1945. 

Div. 8-603.1-M15 

24. Coats to Restrict the Burning Surface of Molded Composite 
Propellant Charges, W. K. McEwen, OSRD 5588, OEMsr- 
202 and OEMsr-639, Service Projects AC-75 and OD-198, 


ERL, Carnegie Institute of Technology and Monsanto 
Chemical Company, Dec. 4, 1945. Div. 8-603. 1-M 16 

25. Molded Composite Propellants for Artillery Rockets, R. A. 

Ruehrwein and Rodger L. Schaefer, OSRD 5701, OEMsr- 
639, Service Project OD-14, Monsanto Chemical Company, 
Nov. 29, 1945. Div. 8-603. 1-M9 

26. Pilot Plant Pressing of Molded Composite Propellant, S. A, 
Francis, OSRD 5702, OEMsr-639, Service Projects AC-75 
and OD-198, Monsanto Chemical Company, Nov. 5, 1945. 

Div. 8-603. 1-M2 

27. Process Report on Pilot Plant Production of Molded Com- 

posite Propellant for ACL-1 Charges, Walter H. Hammond 
and Rodger L. Schaefer, OSRD 5706, OEMsr-639, Service 
Projects AC-75 and 00-198, Monsanto Chemical Com- 
pany, Nov. 29, 1945. Div. 8-603. 1-M 10 

28. Milling of Composite Propellant Molding Powder, W. M. 
Hutchinson, OSRD 5709, OEMsr-639, Service Project 
OD-198, Monsanto Chemical Company, Nov. 29, 1945. 

Div. 8-603. 1-M 11 

29. A Turbidity Method for Determining Particle Size of Po- 
tassium Nitrate, F. A. Long and G. Long, OSRD 5697, 
OEMsr-639, Service Project OD-198, Central Research 
Laboratory, Monsanto Chemical Company, Nov. 23, 1945. 

Div. 8-601-M9 

30. An Apparatus for the Determination of Particle Size, F. A. 
Long, OSRD 590, Service Project OD-04, May 15, 1942. 

Div. 8-110.4-M3 

31. Ultrasonic Inspection of Grains of Molded Composite Pro- 

pellant, J. N. Addams and H. L. Greenwald, OSRD 5699, 
OEMsr-639, Service Project OD-198, Monsanto Chemical 
Company, Nov. 20, 1945. Div. 8-603. 1-M7 

32. Investigation of a Drum Dryer Method of Producing Com- 
posite Propellant Molding Powder, W. B. Dunlap, OSRD 
5696, OEMsr-639, Service Projects AC-75 and OD-198, 
Monsanto Chemical Company, Nov. 5, 1945. 

Div. 8-603.1-M3 

33. High-Pressure Clamping for Assembly of Solid Charges of 
Molded Composite Propellant, F. A. Long and C. E. Norton, 
OSRD 5708, OEMsr-639, Service Project OD-198, Mon- 
santo Chemical Company, Nov. 30, 1945. 

Div. 8-603.1-M12 

34. Recommendations for Future Developmental Work on Molded 

Composite Propellants, F. A. Long, OSRD 6308, OEMsr- 
639, Service Project OD-198, Monsanto Chemical Com- 
pany, Nov. 30, 1945. Div. 8-603.1-M14 

35. Studies Relating to the Stability of Pilot Lots of Rocket Pro- 

pellant Powders, Josephine Bonner and John W. Otvos, 
OSRD 5955, OEMsr-881, Service Project OD-158, CIT, 
Nov. 28, 1945. Div. 8-602.2-M17 

36. Investigation of Double-Base Powders, Linus Pauling, 

Robert B. Corey, and others, OEMsr-881, Monthly Re- 
port for September 1944, CIT, January 1943 to August 
1945, p. 126. Div. 8-604.2-Ml 

37. Investigation of Double-Base Powders, Linus Pauling 

Robert B. Corey, and others, OEMsr-881, Monthly Re- 
port for February 1945, CIT, January 1943 to August 
1945, p. 119. Div. 8-604.2-Ml 

38. The Development and Properties of Large, Long-Burning 

Grains of Composite Propellants, F. A. Long, OSRD 3325, 
OEMsr-202, Service Projects OD-14 and AC-75, Report 
to Feb. 10, 1944, ERL, Carnegie Institute of Technology, 
Mar. 7, 1944. Div. 8-603-M8 

39. Non-Setting Binders for Molded Composite Propellants, 
W. M. Hutchinson, OSRD 5586, OEMsr-202 and OEMsr- 
639, ERL, Carnegie Institute of Technology and Mon- 
santo Chemical Company, Dec. 26, 1945. 

Div. 8-603.1-M17 


UONFIDENTIALl 


168 


BIBLIOGRAPHY 


40. Development of Twelve-inch Diameter Grains of Molded 

Composite Propellants, F. A. Long, OSRD 5698, OEMsr- 
639, Service Projects AC-75 and OD-198, Monsanto Chem- 
ical Company, Nov. 8, 1945. Div. 8-603. 1-M4 

41. Characteristics of the ACL-1 Jet Propidsion Unit, F. A. 

Long, OSRD 5268, OEMsr-639, Service Projects AC-75 
and OD-198, ERL, Monsanto Chemical Company, 
June 27, 1945. Div. 8-607.6-M3 

42. Supplementary Report on the ACL-1 Jet Propulsion Unit, 

Units T-10 and T-lOEl, F. A. Long, OSRD 5703, OEMsr- 
639, Service Project AC-75, Monsanto Chemical Com- 
pany, Nov. 9, 1945. Div. 8-607. 6-M4 

43. Large Thrust Jet Units with 4-second Burning Time, R. A. 

Ruehrwein, OSRD 6307, OEMsr-639, Service Projects 
AC-75 and OD-198, Monsanto Chemical Company, 
Nov. 14, 1945. Div. 8-607.6-M5 

44. Characteristics of Low-Thrust, Long-Burning Jet Propulsion 
Units Utilizing Molded Composite Propellant, R. A. Ruehr- 
wein, OSRD 5705, OEMsr-639, Service Project OD-198, 
IMonsanto Chemical Company, Nov. 20, 1945. 

Div. 8-603. 1-M8 

45. The Decipede, a 100-pound Thrust, 43-second Burning 

Time, Jet Propulsion Unit, J. F. Dewald, OSRD 5704, 
OEMsr-639, Service Project OD-198, Monsanto Chemical 
Company, Nov. 20, 1945. Div. 8-607.6-M6 

46. Development and Testing of Rocket Propellants other than 

Double-Base Powders, Louis P. Hammett, OSRD 438, 
OEMsr-202, Service Project OD-14, Progress Report 199, 
to Feb. 7, 1942, Carnegie Institute of Technology, Mar. 6, 
1942. Div. 8-607.5-Ml 

47. Development and Testing of Composite Rocket Propell- 
ants, Louis P. Hammett, OSRD 857, OEMsr-202, Service 
Project OD-14, Progress Report 354, to July 31, 1942, 
Carnegie Institute of Technology, Sept. 7, 1942. 

Div. 8-607.5-M3 

48. Development of Plastic Mixtures for Use as UP Propellants, 

Charles Allen Thomas and Carrol A. Hochwalt, OSRD 
778, OEMsr-194, Service Project OD-14, Progress Report 
312 to June 30, 1942, Monsanto Chemical Company, 
Aug. 8, 1942. Div. 8-607. 1-Ml 

49. A Condenser Gage Apparatus for Measuring the Pressure and 
Thrust Characteristics of Jet Propulsion Motors, Charles G. 
Sage, OSRD 1678, OEMsr-639 and OEMsr-202, Service 
Project OD-14, ERL, Carnegie Institute of Technology, 
and Monsanto Chemical Company, Aug. 5, 1943. 

Div. 8-607.6-Ml 

50. Rifle Bullet Tests on Composite Propellant 218-B and on 

Ballistite, Henry Posner, Jr., OSRD 1706, OEMsr-202, 
Service Project OD-14, ERL, Carnegie Institute of Tech- 
nology, Aug. 12, 1943. Div. 8-603-M3 

51. Tests of Methods of Mounting Grains of Composite Propel- 
lant 218-B in a Rocket Motor, Henry Posner, Jr., OSRD 
1708, OEMsr-202, Service Project OD-14, ERL, Carnegie 
Institute of Technology, Aug. 12, 1943. Div. 8-603-M2 

52. The Compression Strength of Composite Propellants, F. A. 
Long, OSRD 1758, OEMsr-202, Service Project OD-14, 
ERL, Carnegie Institute of Technology, Aug. 31, 1943. 

Div. 8-603-M4 

53. Variation of Burning Properties of Composite Propellants 

with Temperature, Charles G. Sage, OSRD 1815, OEMsr- 
202, Service Project OD-14, ERL, Carnegie Institute of 
Technology, Sept. 18, 1943. Div. 8-601-M2 

54. Compression Strength of Grains of Composite Propellant 
218-B Prepared at the Monsanto Pilot Plant, F. A. Long, 
OSRD 3076, OEMsr-202, Service Project OD-14, ERL, 
Carnegie Institute of Technology, Jan. 1, 1944. 

Div. 8-603-M6 

55. Purge Pellet W ork at the Explosives Laboratory, F. A. Long, 


OSRD 3184, OEMsr-202, Service Project OD-14, Prog- 
ress Report to Nov. 20, 1943, ERL, Carnegie Institute 
of Technology, Jan. 27, 1944. Div. 8-603-M7 

56. The Flow and Friction Properties of Composite Propellant 
218 and Similar Compositions, Walter Kauzmann, OSRD 
3281, OEMsr-202, Service Project OD-14, ERL, Carnegie 
Institute of Technology, Feb. 14, 1944. Div. 8-603. 1-Ml 

57. The Screw Extrusion of Composite Propellants, Walter 
Kauzmann, OSRD 3282, OEMsr-202, Service Project 
OD-14, ERL, Carnegie Institute of Technology, Feb. 14, 

1944. Div. 8-603.2-M2 

58. Heats of Coinbustion, Heats of Explosion and Burning Rates 

of Ammonium Picrate-Potassium Nitrate Composite Pro- 
pellants, R. W. Broge, OSRD 5585, OEMsr-202, Service 
Project OD-14, ERL, Carnegie Institute of Technology, 
Nov. 15, 1945. Div. 8-601-M7 

59. The Use of General Motors Capacitance Pressure Gages for 
Internal Ballistics Measurements on Rocket Propellants, 
Charles G. Sage, OSRD 5750, OEMsr-202, Service Project 
OD-14, ERL, Carnegie Institute of Technology, Nov. 1, 

1945. Div. 8-607.5-M5 

60. Preliminary Engineering Report on the Manufacture of 
Composite Propellant 218-B, E. H. Buford, Ira Phelps, and 
A. E. Marshall, OSRD 1822, OEMsr-639, Service Project 
OD-14, Monsanto Chemical Company, Sept. 20, 1943. 

Div. 8-603-M5 

61. Purge Pellets for Use with Spinner Rockets Equipped with 
Variable-Time Fuzes, J. N. Addams and Rufus W. Lumry, 
OSRD 5590, OEMsr-639, Service Project OD-14, Mon- 
santo Chemical Company, Nov. 20, 1945. Div. 8-705-M2 

62. Construction at the Monsanto Pilot Plant for Molded Com- 
posite Propellants, R. E. Lenz and W. R. Schwandt, OSRD 
5707, OEMsr-639, Service Projects AC-75, OD-14, and 
OD-i98, Monsanto Chemical Company, Nov. 15, 1945. 

Div. 8-603. 1-M6 

63. Design of Motors for Large-Diameter Charges of Molded 
Composite Propellant, J. F. Dewald and C. E. Norton, 
OSRD 5722, OEMsr-639, Service Projects AC-75 and 
OD-198, Monsanto Chemical Company, Nov. 30, 1945. 

Div. 8-603. 1-M 13 

64. Humidity-Controlled Circuit Breaker, E. H. Epprecht, 
OSRD 3412, OEMsr-1145, Service Project OD-14, Gulf 
Research and Development Company, Mar. 27, 1944. 

Div. 8-607.5-M4 

65. The Preparation and Properties of Solvent-Extruded Com- 
posite Propellants, G. C. Parkinson, B. P. Dailey, and J. F. 
Kincaid, OSRD 5576, OEMsr-202, Service Project OD-14, 
ERL, Carnegie Institute of Technology, Jan. 17, 1946. 

Div. 8-603.2-M8 

66. The Properties and Applications of EJ Powders, R. A. 
Ruehrwein, Rufus W. Lumry and J. F. Kincaid, OSRD 
4053, OEIVIsr-202, Service Project OD-14, ERL, Carnegie 
Institute of Technology, Sept. 5, 1944. Div. 8-603. 2-M3 

67. The Grinding, Classification and Particle-Size Control of 

Crystalline Ingredients for Solvent-Extruded Composite Pro- 
pellants, R. C. C. St. George, Jr., OSRD 5578, OEMsr-202, 
Service Projects OD-14 and OD-200, ERL, Carnegie In- 
stitute of Technology, Oct. 24, 1945. Div. 8-603. 2-M5 

68. The Techniques of Preparation of Solvent-Extruded Com- 

posite Propellants, T. F. Anderson, OSRD 5579, OEMsr- 
202, Service Project OD-14, ERL, Carnegie Institute of 
Technology, Jan. 15, 1946. Div. 8-603. 2-M7 

69. Procedures for the Analysis of EJA Powders, Richard M. 
Noyes and W. A. Schroeder, OSRD 4581, OEMsr-881, 
Service Projects OD-14 and OD-158, CIT, Jan. 24, 1945. 

Div. 8-603.2-M4 

70. Surveillance of Propellants, F. H. Westheirner and Harold 
Salwin, OSRD 5594, OEMsr-202, Service Projects OD-14, 


CoA'l-IDENTIAlj 


BIBLIOGRAPHY 


169 


()I)-158, and N()-274, Progress Roi)ort to Sept. 1, 1945, 
ERL, Carnegie Institute of Technology, Oct. 30, 1945. 

Div. 8-603.2-MG 

71. Ballistic Characteristics and Rocket Design Data for Ex- 
truded Composite Propellants, An Addendum to the Report 
on Solvent Extruded Composite Propellants — OSRD 5576, 
Rufus Luinry and L. N. Streff, OSRD 5624, OEMsr- 
273 and OEMsr-202, Service Project OD-14, NDRC 
Division 3 and Division 8 Report P-10.1, Allegany Ballis- 
tics Laboratory, George Washington University, ERL, 
Carnegie Institute of Technology, December 1945. 

Div. 3-370-M3 

72. Development of the T-4 Powder Charge for the 2.36" Rocket 

Grenade, Rufus Lumry and L. X. Streff, OSRD 5589, 
OEMsr-202 and OEMsr-273, Service Projects OD-14 and 
OD-200, ERL, Carnegie Institute of Technology and 
Allegany Ballistics Laboratory, George Washington Uni- 
versity, Xov. 29, 1945. Div. 8-604.2- ]M6 

73. The Development of a High-Performance Composite-Propel- 

lant Charge for the 115-mm Aircraft Rocket, Rufus W. 
Lumry and L. X. Streff, OSRD 5788, OEIVIsr-273 and 
OEMsr-202, Service Projects XO-245 and OD-14, Divi- 
sion 3 and Division 8 Final Report W-8.4, ERL, and Alle- 
gany Ballistics Laboratory, George Washington Ihiiver- 
sity, December 1945. Div. 3-320-IM5 

74. Cast Perchlorate Propellants Based on Thermo-Setting High 
Polymers, H. F. Hardman and G. B. DeLaMater, OSRD 
5582, OEMsr-202, Service Project OD-198, ERL, Carnegie 
Institute of Technology, Dec. 19, 1945. Div. 8-604. 1-]\I2 

75. Design of a Pilot Plant for the Production of Cast Perchlorate 

Propellant, J. E. Ablard, OSRD 5584, OEMsr-202, Service 
Project OD-198, ERL, Carnegie Institute of Technology, 
Xov. 8, 1945. Div. 8-604. 1-Ml 

76. The Preparation and Properties of Cast Double-Base Pro- 
pellants, B. P. Dailey, J. F. Kincaid, and H. M. Shuey, 
OSRD 5577, OEAIsr-202, Service Project OD-198, ERL, 
Carnegie Institute of Technology, Jan. 15, 1946. 

Div. 8-604.2-M9 

77. Techniques of Preparation of Cast Double-Base Powder, Re- 
strictive Container Fabrication, and Firing of Cast Double- 
Base Charges, H. M. Shuey and R. H. Martin, OSRD 5580, 
OEMsr-202, Service Projects XA-197 and OD-197, ERL, 
Carnegie Institute of Technology, Dec. 26, 1945. 

Div. 8-604.2-M8 

78. Experimental Study of Factors Affecting the Stability and 

Consolidation of Cast Propellant, F. H. Westheimer and 
Edward H. Specht, OSRD 5593, OEMsr-202, Service 
Projects OD-197 and XA-197, ERL, Carnegie Institute of 
Technology, Dec. 12, 1945. Div. 8-604.2-M7 

79. Studies Relating to the Development of Cast Propellants with 

Special Reference to the Mechanism of Consolidation, 
H. Taube and J. L. Hoard, OSRD 5759, OEMsr-229, 
Service Projects OD-05 and XO-135, Cornell University, 
Xov. 6, 1945. Div. 8-604.2-M5 

80. Cast Double-Base Jet Propellard, OSRD 6298, OEMsr- 
1335, Service Project OD-197, E. 1. duPont de Xemours 
and Company, Inc., Xov. 27, 1945. Div. 8-607. 6-M7 

81. Experimental Work on Materials and Design for Nozzles for 
Composite Propellants, L. Axelrod, OSRD 5131, OEMsr- 
202, Service Projects AC-75, OD-14 and OD-198, ERL, 
Carnegie Institute of Technology, Aug. 22, 1945. 

Div. 8-607.7-Ml 

82. Further Experimental Work on Nozzles for Experimerdal 
Testing of Solid Propellants, Motors for Routine Testing of 
Rocket Propellants, L. Axelrod, OSRD 5583, OEMsr-202, 
Service Projects AC-75, OD-14 and OD-198, ERL, Car- 
negie Institute of Technology, Jan. 17, 1946. 

Div. 8-607.7-M2 


83. Special Propellatds, comjnled I)y J. F. Kincaid, George B. 

Kistiakowsky and H. J. Fisher, Service Projects OD-05, 
OD-44, and others. Interim Re])ort SP-8, covering j)eriod 
from A])!*. 15 to May 15, 1943, Sei)tember 1942 to 
August 1945. Div. 8-607-Ml 

84. Flashless Powder for Navy Cannon, OSRD 3726, OEMsr- 

763, Service Project XO-135, Explosives Division, Burn- 
side Laboratory, E. 1. duPont de Xemours and Com- 
pany, Inc., June 3, 1944. Div. 8-605-Ml 

85. Preparation and Properties of Rolled-Sheet Powders Cou- 
taining DINA and other Explosive Plasticizers, Stanley C. 
Burket and A. O. Dekker, OSRD 5466, OEMsr-881, Serv- 
ice Projects OD-158 and XO-274, CIT, Aug. 1, 1945. 

Div. 8-602.3-Ml 

86. “Erosion of Gun Steel by Different Propellants,” John H. 
Hobstetter, Summary Technical Report, XDRC Divi- 
sion 1, Volume 1 Hypovelocity Guns and the Control of 
Gun Erosion, Chap. 15. 

87. Compatibility Relations of N itrocelluloses with Various E.v- 

plosive. Semiexplosive and Non-e.r plosive Materials Perti- 
nent to the Development of Special Propellants, J. L. Hoard, 
H. Taube, and O. X. Salmon, OSRD 5758, OEMsr-229, 
Service Projects OD-05 and XO-135, Cornell University, 
Oct. 30, 1945. Div. 8-606-M9 

88. The Development of an Analytical Procedure for the Chem- 
ical Analysis of Albanite Flashless Powder, OSRD 4035, 
OEIMsr-763, Service Project XO-135, E. I. duPont de 
Xemours and Company, Inc., Aug. 5, 1944. 

Div. 8-605. l-IMl 

89. Albanite Cannon Powder Manufactured at Winnipeg Works 

of Defence Didustries, Ltd., OSRD 5475, OEMsr-763, 
Service Project XO-135, E. 1. duPont de Xemours and 
Company, Inc., Sept. 25, 1945. Div. 8-605. 1-M2 

90. Flashless Powder for Navy Cannon {Final Report), OSRD 
6215, OEMsr-1355, Service Project XO-135, E. I. duPont 
de Xemours and Company, Inc., Dec. 20, 1945. 

Div. 8-605-M2 

91. DINA, Process Development and Semiworks Production, 
OSRD 5975, OEMsr-1332, Service Project XO-135, E. 1. 
duPont de Xemours and Company, Inc., Oct. 12, 1945. 

Div. 8-104-M6 

92. Substitutes for Albanite, F. H. Westheimer and R. H. 

Kallenberger, OSRD 5592, OEMsr-202, Service Projects 
OD-05 and XO-135, ERL, Carnegie Institute of Tech- 
nology, Dec. 5, 1945. Div. 8-605. 1-M3 

93. Special Propellants, compiled by J. F. Kincaid, George B. 

Kistiakowsky, and H. J. Fisher, Service Projects OD-05, 
OD-44, and others. Interim Reports SP-1 through SP-35, 
covering period from Aug. 15, 1942 to Sept. 15, 1945, 
September 1942 to August 1945. Div. 8-607-Ml 

94. Development of Propellants Containing RDX, OSRD 6216, 

OEMsr-1355, Service Project OD-05, Burnside Labora- 
tory, E. I. duPont de Xemours and Company, Inc., 
Dec. 20, 1945. Div. 8-602-M2 

95. Simple Calculation of Thermochemical Properties for Use 
in Ballistics, J. O. Hirschfelder and Jack H. Sherman, 
OSRD 935, OEMsr-51, Service Projects XO-23, PA-230, 
OD-26, and others. Division 1 Progress Report A-101, 
Carnegie Institution of Washington, Oct. 14, 1942. 

Div. 1-210.2-M2 

96. Decrease of Stabilized in Powders, Containing RDX During 

Storage at Elevated Temperatures, Richard M. Lemmon, 
OSRD 5945, OEMsr-881, Service Projects OD-05 and 
OD-158, CIT, Xov. 13, 1945. Div. 8-607-M2 

97. Wood-Cellulose Nitrates for Munitions, George A. Richter, 

OSRD 71, XDCrc-27, Service Project OD-22, Serial 8, 
MIT, Jan. 17, 1941. Div. 8-606-Ml 


GiinFIDENTlAjb 


170 


BIBLIOGR ATH Y 


98. Conversion of Nitrocellulose to Smokeless Powder, George 

A. Richter, OSRD 72, Service Project OD-22, Serial 9, 
MIT, Jan. 17, 1941. Div. 8-607.4-Ml 

99. Mechanism of Gelatinizaiion and Solution of Fibrous Nitro- 
cellulose in Nonaqueous Solvents, J. W. Williams, OSRD 
898, OEMsr-210, Progress Report 373 to Sept. 15, 1942, 
University of Wisconsin, Sept. 25, 1942. Div. 8-606-M2 

100. The Efficiencies of VaHous Substances in Promoting the 
Gelatinizaiion of Nitrocellulose in 2:1 Ether-Ethanol, F. A. 
Long, J. G. Kirkwood and J. L. Hoard, OSRD 997, 
OEMsr-229, Service Project OD-44, Progress Report 418, 
to Sept. 15, 1942, Cornell University, Nov. 3, 1942. 

Div. 8-60G-M3 

101. Mechanism of Gelatinizatioji and Solution of Fibrous Nitro- 

cellulose in Nonaqueous Solvents, R. O. Carter, Jr., H. M. 
Shuey and J. W. Williams, OSRD 1385, OEMsr-210, 
Service Project OD-44, University of Wisconsin, May 6, 
1943. Div. 8-606-M4 

102. Investigations of Molecular Weights and Molecular-Weight 
Distribution of Nitrocellulose, Degradation of Nitrocellulose 
in Smokeless Powder; Viscosity, Osmometry and Light- 
Scattering Studies, Richard IM. Badger, Robert H. Baker, 
and others, OSRD 5946, OEMsr-881, Service Projects 
OD-158 and NO-274, CIT, Nov. 29, 1945. Div. 8-606-M10 

103. Investigations of Double-Base Powders, Linus Pauling, 
Robert B. Corey, and others, OEMsr-881, Monthly Re- 
ports covering period from January 1943 to August 1945, 
CIT, January 1943 to August 1945. Div. 8-604. 2-Ml 

104. Investigations of Double-Base Powders, Linus Pauling, 

Robert B. Corey, and others, OEMsr-881, Monthly Re- 
port for August 1944, CIT, January 1943 to August 1945, 
p. 85; Monthly Report for September 1944, pp. 131, 136, 
137, 138. Div. 8-604.2-Ml 

105. Investigations of Double-Base Powders, Linus Pauling, 
Robert B. Corey, and others, OEMsr-881, Monthly Re- 
port for April 1944, CIT, January 1943 to August 1945, 
p. 58; Monthly Report for May 1944, p. 76. 

Div. 8-604.2-Ml 

106. Investigations of Captured German Propellants, William 

Lipscomb, Jr. and Richard M. Noyes, OSRD 5970, 
OEMsr-881, Service Projects OD-158 and NO-274, CIT, 
Oct. 2, 1945. Div. 8-607.3-M6 

107. Investigations of Captured Japanese Propellants, Garman 

Harbottle, Richard M. Noyes, and David P. Shoemaker, 
OSRD 5971, OEMsr-881, Service Projects OD-158 and 
NO-274, CIT, Nov. 13, 1945. Div. 8-607.3-M7 

108. The Characterization and Solubility of Fractionated Wood 
Pulp and Cotto7i-Linters Nitrocellulose, J. W. Williams, 
R. 0. Carter, Jr., H. M. Shuey, and L. J. Costing, OSRD 
4123, OEMsr-210, Service Project OD-44, Report to 
Mar. 1, 1944, University of Wisconsin, Sept. 12, 1944. 

Div. 8-606-M6 

109. U. S. Army Specification 50-14-3B, Feb. 10, 1943. 

110. Cellulose, J. K. Speicher, Vol. 1, 1930, pp. 232-234. 

111. A Capillary-Type Viscometer for Use with Solutions Con- 
taining Volatile Solvents, John Hardy and Richard M. 
Noyes, OSRD 5949, OEMsr-881, Service Projects 
OD-158 and NO-274, CIT, Oct. 4, 1945. Div. 8-606-M8 

112. Investigations of Double-Base Powders, Linus Pauling, 

Robert B. Corey, and others, OEMsr-881, Monthly Re- 
port for September 1944, CIT, January 1943 to August 
1945, p. 159. Div. 8-604.2-Ml 

113. X-Ray Diffraction Studies of Molecular Orientation in 
Double-Base Smokeless Powders Made by the Solvent and 
Solventless Processes, Henri A. Levy, OSRD 1151, OEMsr- 
702, Service Projects OD-14, PA-330, and others. Divi- 
sion 3 Report A-128, CIT, Dec. 26, 1942. Div. 3-361 .42-M3 

114. Investigations of Double-Base Powders, Linus Pauling, 


Robert B. Corey, and others, OEMsr-881, Monthly Re- 
port for July 1943, CIT, January 1943 to August 1945, 
p. 65. Div. 8-604.2-Ml 

115. Investigations of Double-Base Powders, Linus Pauling, 

Robert B. Corey, and others, OEMsr-881, IMonthly Re- 
port for April 1943, CIT, January 1943 to August 1945, 
p. 28; Monthly Report for May 1943, p. 50; Monthly Re- 
port for July 1943, p. 67. Div. 8-604.2-Ml 

116. Equipment and Procedure for the Preparation of Very Small 
Batches of Rolled Sheet Powder, Robert B. Corey and 
Stanley B. Burket, OSRD 4781, OEMsr-881, Service 
Projects OD-14, OD-158 and NO-274, CIT, Mar. 1, 1945. 

Div. 8-607.2-M2 

117. A Laboratory for the Preparation of Small Batches of Sol- 

ventless Double-Base Powder, A. O. Dekker, OSRD 5947, 
OEMsr-881, Service Projects OD-158 and NO-274, CIT, 
Nov. 14, 1945. Div. 8-607.2-M4 

118a. Preparation of Double-Base Propellant for Solventless Ex- 
trusion, Bruce H. Sage, OElMsr-418, Division 3 Report 
JDC-39, CIT, Mar. 1, 1943. Div. 3-361. 1-M4 

118b. Design of Dies for the Extrusion of Solventless Ballistite, 
Bruce H. Sage, OEMsr-418, Division 3 Report JDC-44, 
CIT, May 29, 1943. Div. 3-361.522-Ml 

119. Stabilization of Smokeless Powder by Ethyl Centralite; 

Part I, Transformation Products of Ethyl Centralite in 
Double-Base Powder, Kenneth N. Trueblood, OSRD 
5967, OEMsr-881, Service Projects NO-274 and OD-158, 
CIT, Oct. 30, 1945. Div. 8-602.2-Mll 

120. Stabilization of Smokeless Powder by Diphenylamine; 

Part I, Transformation Products of Diphenylamine in 
Double-Base Powder, W. A. Schroeder, OSRD 5965, 
OEMsr-881, Service Projects OD-158 and NO-274, CIT, 
Nov. 29, 1945. Div. 8-602.2-M18 

121. The Preparation and Plastic Properties of Small Batches of 
Double-Base Powders Containing Nitro Esters of Maleic 
Acid, Earl O. Wilson, OSRD 4430, OEMsr-881, Service 
Projects OD-158 and NO-274, CIT, Dec. 1, 1944. 

Div. 8-607.2-Ml 

122. Investigations of Double-Base Powders, Linus Pauling, 

Robert B. Corey and others, OEMsr-881, Monthly Re- 
port for August 1945, CIT, January 1943 to August 1945, 
p. .78. Div. 8-604.2-Ml 

123. Investigations of the Linear Burning Rates of Propellant 

Powders of Various Compositions, Linus Pauling, OSRD 
5972, OEMsr-881, Service Projects OD-14, OD-158, and 
NO-27, CIT, Dec. 6, 1945. Div. 8-601-M9 

124. Work on Solid Propellant Rockets, Interview of Rudolf 
Edse, F. J. Ewing and M. M. Mills. 

125. Luftfahrtforschungsanstalt, Combined Intelligence Ob- 
jectives Subcommittee, Target No. 25/71, U. S. and Great 
Britain, June 6, 1945. 

126. Investigations of Double-Base Powders, Linus Pauling, 

Robert B. Corey, and others, OEMsr-881, Monthly Re- 
port for September 1944, CIT, January 1943 to August 
1945, p. 106. Div. 8-604.2-Ml 

127. Special Propellants, compiled by J. F. Kincaid, George B. 
Kistiakowsky and H. J. Fisher, Service Projects OD-05, 
OD-44, and others. Interim Report SP-18, Feb. 15 to 
Mar. 15, 1944, September 1942 to August 1945. 

Div. 8-607-Ml 

128a. Bureau of Ordnance Specifications 3383 F-4b(la), 
Sept. 30, 1944. 

128b. Bureau of Ordnance Specifications 3383 F-4b(2), Sept. 
30, 1944. 

128c. Bureau of Ordnance Specifications 3383 F-4b(5b), 
Sept. 30, 1944. 

128d. Bureau of Ordnance Specifications 3383 F-4b(5a), Sept. 
30, 1944. 


CmSTFIDKXTIAli 


BIBLIOGRAPHY 


171 


128e. Bureau of Orduanec Specifications 3383 F-4h(3a), 
Sept. 30, 1944. 

129. Modified Devarda Method for the Determination of Nitrogen 
in Nitrocellulose, R. (). Carter, Jr., H. M. Shuey, and 
J. W. Williams, OSRD 3875, OEIMsr-210, Service Project 
OD-44, University of Wisconsin, July 10, 1944. 

Div. 8-()06-M5 

130. I nvestigations of Double-Base Powders, Linus Pauling, 

Robert B. Corey, and others, OEMsr-881, Monthly Re- 
port for August 1945, CIT, October 1943 to August 1945, 
p. 139. Div. 8-604.2-Ml 

131. X-ray Diffraction Studies of Constituents of Explosives, 

Richard M. Noyes and Maryellin Kates, OSRD 5951, 
OEjMsr-881, Service Projects OD-01, OD-158, and NO- 
274, CIT, Nov. 14, 1945. Div. 8-607.3-M8 

132. “Volumetric Determination of Nitroglycerol and of Ni- 
troglycerol and Dinitrotoluene in Admixture,” W. W. 
Becker, Industnal and Engineering Chemistry, Analytical 
Edition, Vol. 5, 1933, pp. 152-154. 

133. U. S. Army Specifications R-llB, Oct. 28, 1942. 

134. Investigations of Double-Base Powders, Linus Pauling, 

Robert B. Corey, and others, OEMsr-881, Monthly Re- 
port for June 1945, CIT, January 1943 to August 1945, 
p. 62. Div. 8-604.2-Ml 

135. Investigations of Double-Base Powders, Linus Pauling, 

Robert B. Corey, and others, OEMsr-881, Monthly Re- 
port for November 1943, CIT, January 1943 to August 
1945, p. 50; ^Monthly Report for December 1943, p. 72; 
Monthly Report for January 1944, j:). 52; and IVIonthly 
Report for March 1944, p. 50. Div. 8-604.2-Ml 

136. Investigations of Double-Base Powders, Linus Pauling, 

Robert B. Corey, and others, OEMsr-881, Monthly Re- 
port for December 1943, CIT, January 1943 to August 
1945, pp. 69, 70. Div. 8-604.2-Ml 

137. Investigations of Double-Base Powders, Linus Pauling, 
Robert B. Corey, and others, OEMsr-881, Monthly Re- 
port for January 1944, CIT, January 1943 to August 1945, 
pp. 46, 49; Monthly Report for March 1944, p. 48; 
Monthly Report for April 1944, p. 71. Div. 8-604.2-Ml 

138. hwestigations of Double-Base Powders, Linus Pauling, 

Robert B. Corey, and others, OEMsr-881, Monthly Re- 
port for February 1944, CIT, January 1943 to August 
1945, p. 50. Div. 8-604.2-Ml 

139. Examination of Cordite N, NQ, etc., British Laboratory 
Method P. 87, Great Britain. 

140. Examination of Cordite N, NQ, etc., British Laboratory 
Method P/91 A, Great Britain. 

141. Examination of Cordite N, NQ, etc., British Laboratory 
Method P.9E. 

142. Exa^nination of Cordite N, NQ, etc., British Laboratory 
Method 4094, Great Britain. 

143. Picatinny Arsenal Laboratory Report 98187. 

144. Service des Memorial des Poitdres, Henri Pierre Lecorche 
and Jovinet, Vol. 23, 1928, pp. 69-78. 

145. An Improved Volumetric Bromination Procedure for the De- 

termination of Centralite in Smokeless Powder, Garman 
Ilarbottle and Richard M. Noyes, OSRD 4820, OEMsr- 
881, Service Projects OD-158 and NO-274, CIT, Mar. 
17, 1945. Div. 8-607.4-M2 

146. Investigations of Double-Base Powders, Linus Pauling, 
Robert B. Corey, and others, OEMsr-881, Monthly Re- 
port for February 1943, CIT, January 1943 to August 
1945, p. 15; Monthly Report for April 1943, pp. 19-27; 
Monthly Report for May 1943, p. 47. Div. 8-604.2-Ml 

147. Investigations of Double-Base Powders, Linus Pauling, 

Robert B. Corey, and others, OEMsr-881, Monthly Re- 
port for June 1945, CIT, January 1943 to August 1945, 
p. 65. Div. 8-604.2-Ml 


148. The Relationship between the Quantities of “Total,’’ “Avail- 

able,” and “Actual,” Diphenylamine in Smokeless Powders, 
Allan L. Grossberg and Richard M. Noyes, OSRD 5948, 
OEMsr-881, Service Projects NO-274 and OD-158, CIT, 
Nov. 13, 1945. Div. 8-607.4-M4 

149. Industrial and Engineering Chemistry, Analytical Edition, 
Stanley G. Cook, 'Vol. 7, 1935, pi). 250-255. 

150. An Improved Volumetric Method for the Determination of 
Diphenylamine in Nitrocellulose Powders, OSRD WA- 
4296-7, HOL Report 116, Naval Ordnance Inspection 
Laboratory, Holton Heath, Eng., Mar. 31, 1945. 

151. “Determination of Phthalate Plasticizers,” F. C. Thames, 
Industnal and Engineering Chemistry, Analytical Edition, 
Vol. 8, 1936, pp. 418-419. 

152. A Chromatographic Method for the Analysis of Diethyl- 
phthalate in the Presence of Ethyl Centralite, R. W. Isenses, 
Radford Ordance Works Powder Laboratory, Sept. 4, 1944. 

153. Investigations of Double-Base Powders, Linus Pauling, 
Robert B. Corey, and others, OEMsr-881, Monthly Re- 
l)ort for March 1943, CIT, January 1943 to August 1945, 
j). 18; Monthly Report for May 1943, p. 19. 

Div. 8-604.2-Ml 

154. The Estimation of Moisture in Solventless Double-Base 
Powders, Richard M. Noyes, OSRD 4672, OEMsr-881, 
Service Projects OD-158 and NO-274, CIT, Feb. 8, 1945. 

Div. 8-602. 1-M2 

155. Picatinny Arsenal Tentative Specifications PXS-633, Re- 
vision 5, Dec. 16, 1941. 

156. Journal of the American Chemical Society, D. M. Smith, 
W. M. D. Bryant, and J. Mitchell, Jr., Vol. 61, 1939, 
p. 2409. 

157. Procedures for the Estimation of Inorganic Constituents in 
Double-Base Powders, Allan L. Grossberg, Joseph C. 
Guffy, and others, OSRD 5950, OEMsr-881, Service 
Projects OD-158 and NO-274, CIT, Nov. 29, 1945. 

Div. 8-607.4-M7 

158. Polarographic Divestigation of Single-Base Powders, V. W. 
Meloche, OSRD 5751, OEMsr-1040, Service Project OD- 
118, University of Wisconsin, Jan. 15,1946. Div.8-602-M3 

159. Chromatographic Studies of Double-Base Powders, I, 
Robert B. Corey, R. B. Escue, A. L. Le Rosen, and W. A. 
Schroeder, OSRD 1152, OEMsr-702, Service Projects 
OD-14, OD-26, and others. Division 3 Armor and Ord- 
nance Report A-132, CIT, Jan. 2, 1943. Div. 3-361. 31-M2 

160. Chromatographic Studies of Smokeless Powders and Re- 

lated Substances, Part I, Robert B. Corey, A. O. Dekker, 
and others, OSRD 1837, OEMsr-881, Service Project 
OD-05, CIT, Sept. 25, 1943. Div. 8-602.4-Ml 

161. Chromatographic Studies of Smokeless Powder and Related 

Substances, Part II, Robert B. Corey and W. A. Schroeder, 
OSRD 4431, OEMsr-881, Service Projects OD-158 and 
NO-274, CIT, Dec. 6, 1944. Div. 8-602.4-M2 

162. Chromatographic Studies of Smokeless Powder and Related 

Substances, Part III, Kenneth N. Trueblood, OSRD 
5952, OEMsr-881, Service Projects OD-158 and NO-274, 
CIT, Nov. 14, 1945. Div. 8-602.4-M4 

163. Absorption Spectra of Explosives and other Compounds of 
Interest in the Study of Smokeless Powder, Rene Scott 
Mills and Philip E. Wilcox, OSRD 5953, OEMsr-881, 
Service Projects NO-274, and OD-158, CIT, Oct. 30, 1945. 

Div. 8-607.4-M3 

164. Investigations of Double-Base Powders, Speclrophotometric 

Studies, I, Robert B. Corey, A. O. Dekker, and A. M. 
Soldate,' OSRD 1103, OEMsr-702, Service Projects OD- 
14, PA-330, and others. Division 3 Progress Report A-124, 
CIT, Dec. 16, 1942. Div. 3-361.32-Ml 

165. Investigations of Double-Base Powders, Part II, Spectro- 
photometric Studies, Robert B. Corey, Albert O. Dekker, 


iv 0 N F 1 n E xtTTlI 


172 


BIBLIOGRAPHY 


and A. M. Soldate, OSHJ) 1558, ()EIMsr-7()2, Service 
Projects ()D-14, CWS-22, and others, Division 3 Armor 
and Ordnance Rei)ort A-194, CIT, June 30, 1943. 

Div. 3-361. 32-Ml 

166. The Effect of Processing Operations and of Elevated Tem- 

peratures Upon the Diphenylaniine Content of Ballistite, 
Bruce H. Sage and Linus C. Pauling, OSRD 2298, 
OEiMsr-418, Service Project NO-33, Division 3 Report 
JDC-66, CIT, Sept. 29, 1944. Div. 3-361.51-M8 

167. The Effect of Changes in Composition on the Stability of 

Trench Mortar Increments, Kenneth N. Trueblood, OSRD 
4821, OE]\Isr-881, Service Project OD-158, CIT, Mar. 17, 
1945. Div. 8-602.2-M4 

168. So7ne ExpeHments Dealing with the Effect of Carbon Black 

and Nigrosine on the Stability of Ballistite, Earl O. Wilson, 
OSRD 3783, OEMsr-881, Service Projects OD-14 and 

OD-158, CIT, May 15, 1944. Div. 8-602.2-Ml 

169. The Effect of Variations in Composition on the Stability of 

Ballistite, Kenneth N. Trueblood, OSRD 5418, OEMsr- 
881, Service Projects OD-158 and NO-274, CIT, Aug. 7. 
1945. Div. 8-602.2-M6 

170. Changes in the Percentages of Diphenylamine m Single-and 

Double-Base Powders which had been subjected to Vacuum 
Stability Tests at 110°, 90° and 90° C, Jerry Donohue, 
OSRD 5957, OEMsr-881, Service Projects OD-158 and 
NO-274, CIT, Nov. 28, 1945. Div. 8-602.2-M16 

171. Stabilization of Smokeless Powder by Diphenylamine', 

Part 11, Transfoimation Products of Diphenylamine in 
FNH and Pyro Powder, Laura L. Fong, OSRD 5966, 
OEMsr-881, Service Projects NO-274 and OD-158, CIT, 
Nov. 13, 1945. Div. 8-602.2-M13 

172. NDRC Division 8, British Report HOL 112, File B-5544. 

173. NDRC Division 8, British Report HOL 114, File B-5545. 

174. NDRC Division 8, British Report HOL 115, File B-5879. 

175. NDRC Division 8, British Report HOL 117 and 118, 
File B-5932. 

176. NDRC Division 8, British Report HOL 121, File B-6090. 

177. A Chromatographic Study of RDX and Related Substances, 
Earl W. Malmberg, OSRD 5943, OEMsr-881, Service 
Project OD-12, CIT, Nov. 13, 1945. Div. 8-602.4-M3 

178. A Chromatographic Investigation of the Impunties in Cer- 

tain Samples of Commercial RDX, Earl W. Malmberg, 
OSRD 5944, OEMsr-881, Service Project OD-12, CIT, 
Nov. 13, 1945. Div. 8-110.4-M7 

179. Surveillance Testing of Propellant Explosives, Hyman 

Henkin, OSRD 4103, OEMsr-202, Service Projects OD- 
01, OD-05, and others, ERL, Carnegie Institute of Tech- 
nology, Sept. 5, 1944. Div. 8-602.2-M2 

180. Studies Relating to the Stability of Pilot Lots of Rocket 

Propellant Powders, Josephine Bonner and John W. Otvos, 
OSRD 5955, OEMsr-881, Service Project OD-158, CIT, 
Nov. 28, 1945. Div. 8-602.2-M17 

181. A n Investigation of the Possible Correlation of Changes in 
Color with the Condition and Stability of Certain Production 
Lots of Stick Powder, Jerry Donohue, OSRD 5533, OEMsr- 
881, Service Project OD-158, CIT, Sept. 28, 1945. 

Div. 8-602.2-M8 

182. Studies on the Condition and Stability of 7 ! 8-inch Stick 

Powder Cordaining 100- percent rework, Jerry Donohue, 
OSRD 5969, OEMsr-881, Service Project OD-158, CIT, 
Sept. 21, 1945. Div. 8-602.2-M7 

183. Critical Evaluation of Results of the Application of the 

Vacuum Stability Test to Smokeless Powder, Jerry Dono- 
hue and William N. Lipscomb, Jr., OSRD 5963, OEMsr- 
881, Service Projects OD-158 and NO-274, CIT, Dec. 6, 
1945. Div. 8-602.2-M19 

184. Vacuum Stability Tests on Solventless Double-Base Powders 
CoiUaining Various Stabilizers, Philip Hayward, OSRD 


5959, OEMsr-881, Service Projects NO-274 and OD-158, 
CIT, Nov. 20, 1945. Div. 8-602.2-M15 

185. ‘'The Velocity of Decomposition of High Explosives in a 
Vacuum, Part II Trinitrophenylmethylnitroamine (Tet- 
ryl),” Robert Crosbie Farmer, Journal of the Chemical 
Society, Vol. 117, 1920, pp. 1432, 1603-1614. 

186. “The Velocity of Decomposition of High Explosives in a 
Vacuum. Part III Mercuric Fulminate,” Robert Crosbie 
Farmer, Journal of the Chemical Society, Vol. 121, 1922, 
pp. 174-187. 

187. Chemical Tests for New Explosives, Russell McGill, 

OSRD 787, OEMsr-202, Service Project OD-01, Rei)ort 
305, to July 1, 1942, Carnegie Institute of Technology, 
Aug. 25, 1942. Div. 8-201-Ml 

188. Vacuum Stability Tests on Experimental Powders Contain- 
ing Manganese Dioxide, David P. Shoemaker and Jerry 
Donohue, OSRD 4970, OEMsr-881, Service Projects OD- 
158 and NO-274, CIT, Apr. 23, 1945. Div. 8-604.2-M4 

189. Vacuum Stability Tests on Experwiental Powders Contain- 
ing Phthalide, David P. Shoemaker, OSRD 4971, OEMsr- 
881, Service Project NO-274, CIT, Apr. 23, 1945. 

Div. 8-607.2-M3 

190. Development of a Vacuum Stability Test for Double-Base 

Powders, William N. Lipscomb, Jr., OSRD 5149, OEMsr- 
881, Service Projects OD-158 and NO-274, CIT, May 30, 
1945. Div. 8-602.2-M5 

191. Development of a Vacuum Stability Test for Double-Base 

Powder, William N. Lipscomb, Jr., OSRD 5954, OEMsr- 
881, Service Projects OD-158 and NO-274, CIT, Oct. 18, 
1945. Div. 8-602.2-M9 

192. Studies of the Effect of Various Salts on the Vacuum Sta- 
bility Behaviour of Solventless Double-Base Powders, 
Philip Hayward, OSRD 5960, OEMsr-881, Service Pro- 
jects NO-274 and OD-158, CIT, Nov. 13, 1945. 

Div. 8-602.2-M12 

193. Vacuum Stability Tests on Solventless Double-Base Powd- 

ers Containing Vaiious Stabilizers, Philip Hayward, 
OSRD 5959, OEMsr-881, Service Projects NO-274 and 
OD-158, CIT, Nov. 20, 1945. Div. 8-602.2-M15 

194. A Nomogram for Calculation of Results of Vacuum Sta- 

bility Tests, Jerry Donohue and Fred D. Ordway, OSRD 
5964, OEMsr-881, Service Projects OD-158 and NO-274, 
CIT, Oct. 19, 1945. Div. 8-602.2-M10 

195. Compositions of Gases Evolved by Smokeless Powders in 

Vacuo at Elevated Temperatures, Victor SclTocken,OSRD 
5956, OEMsr-881, Service Projects NO-274 and OD-158, 
CIT, Nov. 16, 1945. Div. 8-607.4-M5 

196. A New Apparatus for Studying the Stability of Smokeless 
Powders, A Highly-Modified For7n of the Taliani Test, 
Victor Schocken, OSRD 5961, OEMsr-881, Service Pro- 
jects NO-274 and OD-158, CIT, Nov. 16, 1945. 

Div. 8-602.2-M14 

197. Zeitschrift fiir das Gesa7nte Schiess- 7i7id Sprengstoffwesen, 
Angeli, Vol. 17, 1922, p. 115. 

198. Revue des Materiels Plastiques, Deribere, Vol. 10, 1934, 
p. 260; Vol. 12, 1936, p. 356. 

199. Dansk Artillerie Tidsskr7'ist, Hansen, Vol. 12, 1935, p. 129. 

200. “Stabilitetsundersgelser paa Krudt og Skydebomuld ved 
Hjaelp af Brintionmaalinger,” N. L. Hansen, III Nord- 
iska Kemistmotet Jlelsmgfors Juli 13-16, 1926, Fb7'hand- 
lingar och Foredrag, Helsingfors, Finland, 1928, j)]). 227- 
230. 

201. Zeitschrift fiir das Gesarnte Schiess- imd Sprengstoffwesen, 
Metz, Vol. 21, 1926, p. 186; Vol. 24, 1929, pp. 245, 291, 
335; Vol. 27, 1932, pp. 118, 150, 188; Vol. 29, 1934, 
p. 361. 

202. Jahresbericht der Che7nische-Technischen Reichsanstalt, 
Metz, Lenze, Rubens, Vol. 8, 1930, p. 26. 




BIBLIOGRAPHY 


173 


203. Measurements of pH on Smokeless Powders, Linus Pauling, 

OSRD 5968, OEMsr-881, Service Projects OD-158 and 
NO-274, CIT, Nov. 28, 1945. Div. 8-602-Ml 

204. A Magazine of New Design for Conducting 65.5° C Surveil- 

lance Tests on Smokeless Powders, Austin L. Wahrhaftig, 
OSRD 5962, OEMsr-881, Service Projects NO-274 and 
OD-158, CIT, Nov. 23, 1945. Div. 8-607.4-M6 

205. L^. S. Army Tentative Specifications AXS-719, Revision 
3, Ordnance Department, Dec. 16, 1942. 

206. I". S. Army Specification R-llB,Oct. 28, 1942; Addendum 
4 to 50-12-3, Superseding R-llA. 

207. Investigations of Double-Base Powders, Linus Pauling, 
Robert B. Corey, and others, OEMsr-881, Monthly Re- 
l^ort for September 1944, CIT, January 1943 to August 

1945, p. 82. Div. 8-604.2-Ml 

208. A Proposed Device for Indicating the Condition of the Pro- 
pellant Charge in Rocket Motors on Shipboard or in the 
Field, Jerry Donohue, OSRD 5958, OEMsr-881, Service 
Project NO-274, CIT, Nov. 13, 1945. Div. 8-607.5-M6 

209. Investigations of Double-Base Powders, Linus Pauling, 
Robert B. Corey, and others, OEMsr-881, Monthly Re- 
port for April 1945, CIT, October 1943 to August 1945, 
p. 81; Monthly Report for August 1945, p. 161. 

Div. 8-604.2-Ml 

210. ARD Explosives Report 655/44, Armament Research 
Department, Great Britain, August 1944. 

211. An Investigation of the Propellant Taken from a Captured 
21-cm German Rocket, David P. Shoemaker, OSRD 5973, 
OEMsr-881, Service Project OD-158, CIT, Dec. 6, 1945. 

Div. 8-607. 3-M9 

212. Direct Measurement of Burning Rates by an Electric Tim- 

ing Method, Bryce L. Crawford, Jr. and Clayton M. 
Huggett, OSRD 4009, OEMsr-716, Division 3 Armor and 
Ordnance Report A-286, L^niversity of Minnesota, Aug. 
6, 1944. Div. 3-612-M3 

213. F. J. Ewing and M. M. Mills, OSRD WA-4597-12R, 
Technical Intelligence Report 1-52, U. S. Strategic Air 
Forces in Europe, June 6, 1945. 

214. Thermochemical Examination of a Number of Commercial 
and Experimental Propellants, J. F. Kincaid and B. P. 
Dailey, OSRD 1578, OEMsr-202, Service Project OD-05, 
Progress Report to May 15, 1943, ERL, Carnegie Insti- 
tute of Technology, July 8, 1943. Div. 8-602.1-Ml 

215. Thermochemical Studies of Special Propellants, OSRD 
6217, OEMsr-1355, Service Projects OD-05 and NO-135, 
E. I. duPont de Nemours and Company, Inc., Jan. 16, 

1946. Div. 8-602. 1-M5 

216. An Apparatus for the Arrested Burning of Gun Propellants, 

J. F. Kincaid and B. P. Dailey, OSRD 1836, OEMsr-202, 
Service Project OD-05, ERL, Carnegie Institute of Tech- 
nology, Sept. 22, 194k Div. 8-601-M3 

217. Closed Bomb Burning of High Explosives and Propellants, 

S. J. Jacobs and W. B. Buck, OSRD 6329, OEMsr-202, 
Service Project OD-04, ERL, Carnegie Institute of Tech- 
nology, Jan. 22, 1946. Div. 8-500-M3 

218. Intermediate Burning Products of Nitrocellulose, M. L. 
Wolfrom and Robert C. Elderfield, OSRD 3568, OEMsr- 
1152 and OEMsr-137, Service Project OD-126, Ohio State 
University and Columbia University, May 3, 1944. 

Div. 8-203-M3 

219. The Thermal Decomposition of Cellulose Nitrate Under Re- 

duced Pressure, Chemical Nature of the White Substance 
(IF>S'), M. L. Wolfrom, E. E. Dickey, D. D. Hoffman, 
and S. M. Olin, OSRD 4999, OEMsr-1152, Service Pro- 
ject OD-126, Report to February 28, 1945, Ohio State 
University, Apr. 28, 1945. Div. 8-606-M7 


220. Extrusion of Cordite at Explosive Research Laboratory, 
J. E. Ablard, OSRD 1336, OEMsr-202, Service Project 
NO-99, Progress Report to March 1, 1943, ERL, Carnegie 
Institute of Technology, Apr. 10, 1943. Div. 8-603. 2-Ml 

221. Extrusion of a Special British Cordite Sample, R. H. Kal- 

lenberger and J. E. Ablard, OSRD 1754, OEMsr-202, 
Service Project NO-99, ERL, Carnegie Institute of Tech- 
nology, Aug. 31, 1943. Div. 8-607. 3-M4 

222. Extrusion of Ballistite at the Explosives Research Labora- 

tory, J. E. Ablard, OSRD 4007, OEMsr-202, Service Pro- 
ject NO-90, ERL, Carnegie Institute of Technology, 
Aug. 11, 1944. Div. 8-004.2-M2 

223. Inhibition of Nitroglycerine Diffusion in Coatings for Re- 

stricting Burning of Rocket Propellants, Rufus W. Lumry, 
OSRD 1995, OEMsr-202, Service Project OD-14, Explo- 
sives Research Laboratory, Carnegie Institute of Tech- 
nology, Nov. 5, 1943. Div. 8-601-M4 

224. The Separation of Nitroglycerine from Double-Base Powd- 

ers, A Preliminary Literature Survey, F. H. Westheimer, 
OSRD 4791, OEMsr-202, Service Project OD-01, Ex- 
plosives Research Laboratory, Carnegie Institute of 
Technology, Mar. 9, 1945. Div. 8-604.2-M3 

225. The Separation of Nitroglycerin from Double-Base Powders, 
F. H. Westheimer, OSRD 5591, OEMsr-202, Service 
Project OD-01, Explosives Research Laboratory, Car- 
negie Institute of Technology, Nov. 1, 1945. 

Div. 8-602. 1-M3 

226. Spontaneous Ignitors for Gasoline-Fuming Nitric Acid 

Mixtures, Eugene E. Ayres, OSRD 777, OEMsr-322, 
Service Project NA-103, Progress Report 310, to July 16, 
1942, Gulf Research and Development Company, Aug. 
6, 1942. Div. 8-702-Ml 

227. Spontaneous Ignitors for Gasoline-Fuming Nitric Acid 

Mixtures, Eugene E. Ayres, OSRD 1000, OEMsr-322, 
Service Project NA-103, Final Report 421, to Sept. 30, 
1942, Gulf Research and Development Company, Nov. 
4, 1942. Div. 8-702-M2 

228. New and Improved Syntheses of Miscellaneous Organic 

Compounds, Philip E. Wilcox, ()SRD 5974, OEMsr-881, 
Service Projects NO-274 and OD-158, CIT, Nov. 27, 
1945. Div. 8-602. 1-M4 

229. The 32° Transition of Ammonium Nitrate, J. F. Kincaid 

and R. C. C. St. George, OSRD 1577, OEMsr-202, Serv- 
ice Projects OD-05 and OD-14, ERL, Carnegie Institute 
of Technology, July 7, 1943. Div. 8-110.3-M3 

Chapter 7 

1 . Tracer Research at the Explosive Research Laboratory, Walter 

Kauzmann, OSRD 3283, OEMsr-202, Service Projects 
NO-151 and OD-159, ERL, Carnegie Institute of Tech- 
nology, Feb. 14, 1944. Div. 8-701-M2 

2 . Review of Igniter and Tracer Compositions, OSRD 3498, 

OEMsr-1226, Service Projects OD-159 and NO-151, Report 
to Mar. 15, 1944, Metal and Thermit Corporation, Apr. 21, 
1944. Div. 8-701-M3 

3. Tracer and Igniter Compositions, OSRD 6581, OEMsr-1226, 

Service Projects NO-151 and OD-159, Metal and Thermit 
Corporation, Jan. 15, 1946. Div. 8-700-Ml 

4. Polarographic Analysis of Primers, James J. Lingane, OSRD 

4881, OEMsr-1028, Service Project OD-118, Harvard Uni- 
versity, Mar. 30, 1945. Div. 8-703-M2 

5. The Microscopical Examination of Primer Compositions, 
Alfred T. Blomquist, OSRD 3757, OEMsr-193, Service 
Project OD-109, Cornell University, Aug. 1, 1944. 

Div. 8-703-Ml 


BTOXF I DHNT r.VTD 


OSRD APPOINTEES 

Division 8 


Chiefs 

G. B. Kistiakowsky 
R. A. Connor 


S. R. Aspinall 
A. H. Blatt 
R. A. Connor 


Technical Aides 

L. H. Farinholt 
J. R. Johnson 

M. F. Roy 

Wm. C. 0. White 


Members 


W. E. Bachmann 
Walker Bleakney 
R. W. Cairns 
L. H. Farinholt 
R. E. Gibson 
L. P. Hammett 
J. G. Kirkwood 


Section Chiefs 

R. A. Connor 
T. L. Davis 

F. C. Whitmore 


G. B. Kistiakowsky 
W. E. Lawson 

D. P. MacDougall 
Linus Pauling 

H. G. Stone 
C. A. Thomas 

E. B. Wilson, Jr. 


J. R. Johnson 
G. B. Kistiakowsky 


Section Members 


W. E. Bachmann 
A. H. Blatt 
A. T. Blomquist 
Marvin Carmack 
James Cason 
R. H. Cole 
R. C. Elderfield 
L. H. Farinholt 


C. A. Hochwalt 
J. C. Holtz 
J. R. Johnson 
J. F. Kincaid 
F. A. Long 
Russell McGill 
R. L. Shriner 
F. H. Westheimer 

F. C. Whitmore 


174 


U;()\ FIDKXTI A l t 


CONTRACT NUMBERS, CONTRACTORS, AND SUBJECT OF CONTRACT 


Contract Number 


Contractor 


Subject 


NDCrc-4 

University of Chicago 

Chicago, 111. 

Kinetics of nitration 

NDCrc-5 

Harvard University 

Cambridge, IMass. 

Synthesis of aliphatic-aromatic nitro-compounds 

NDCrc-7 

Northwestern University 

Evanston, 111. 

Synthesis of Tetranitromethane 

NDCrc-8 

Pennsylvania State College 

State College, Pa. 

Synthesis of RDX 

NDCrc-12 

Massachusetts Institute of Technology 
Cambridge, Mass. 

Nitration of naphthalene 

NDCrc-19 

Iowa State College 

Ames, Iowa 

Nitration of furans 

NDCrc-21 

University of Michigan 

Ann Arbor, Mich. 

Synthesis of explosives from ethylenediamine 

NDCrc-22 . 

Polytechnic Institute of Brooklyn 

Brooklyn, N. Y. 

Synthesis of aminoguanidine sulfate 

NDCrc-23 

Cornell University 

Ithaca, N. Y. 

Synthesis of cyclic nitro compounds 

NDCrc-24 

Columbia University 

New York, N. Y. 

Synthesis of explosives from amino alcohols 

NDCrc-27 

Massachusetts Institute of Technology 
Cambridge, Mass. 

Nitration of wood pulp 

NDCrc-30 

Harvard University 

Cambridge, Mass. 

Theory of detonations 

NDCrc-35 

Purdue University 

Lafayette, Ind. 

Synthesis of nitroparaffins 

NDCrc-43 

Ohio State University 

Columbus, Ohio 

Synthesis of explosive intermediates obtained by 
formaldehyde condensations 

NDCrc-46 

Harvard University 

Cambridge, Mass. 

Measurement of heats of combustion of explosives 

NDCrc-6G 

Pennsylvania State College 

State College, Pa. 

Synthesis of RDX 

NDCrc-87 

University of Michigan 

Ann Arbor, Mich. 

Synthesis of RDX 

NDCrc-147 

National Academy of Sciences 

Washington, D. C. 

Phase rule diagrams of explosives 

NDCrc-153 

Massachusetts Institute of Technology 
Cambridge, Mass. 

Conversion of nitrocellulose to smokeless powder 

NDCrc-lG2 

Columbia University 

New York, N. Y. 

Syntliesis of explosives from amino alcoliols 

NDCrc-lG8 

Harvard University 

Cambridge, Mass. 

Study of shock waves 

OEMsr-ll 

Carnegie Institute of Technology 

Pittsburgh, Pa. 

Explosives Research Laboratory 

OEMsr-121 

Cornell University 

Ithaca, N. Y. 

Study of shock waves 

OEMsr-137 

Columbia University 

New York, N. Y. 

Synthesis of explosives from amino alcohols 

OEMsr-147 

National Academy of Sciences 

Washington, D. C. 

Separation of nitrotoluenes 

OEMsr-15G 

National Academy of Sciences 

Washington, D. C. 

Phase rule diagrams of explosives 

OEMsr-lG3 

Ohio State Research F oundation 

Columbus, Ohio 

Eutectic diagrams of explosives 

OEMsr-181 

Western Cartridge Co. 

East Alton, 111. 

RDX pilot plant 

OEMsr-193 

Cornell University 

Ithaca, N. Y. 

Synthesis of RDX, DINA, and other nitramines 
and the crystallographic identification of ex- 
plosives 

OEMsr-194 

Monsanto Chemical Company 

Dayton, Ohio 

Plastic binders for moulded composite propellants 


i A [; 7 


175 


CONTRACT NUMBERS, CONTRACTORS, AND SUBJECT OF CONTRACT {Continued) 


Contract Number 


Contractor 


Subject 


OEMsr-202 

Carnegie Institute of Technology 

Pittsburgh, Pa. 

Explosives Research Laboratory 

OEMsr-210 

University of Wisconsin 

Madison, Wis. 

Gelatinization of nitrocellulose 

OEMsr-218 

Institute of Advanced Study 

Princeton, N. J. 

Study of shock waves 

OEMsr-220 

E. I. du Pont de Nemours & Co. 

Wilmington, Del. 

RDX pilot plant 

OEMsr-224 

Columbia University 

Synthesis of explosive intermediates obtained by 


New York, N. Y. 

formaldehyde condensations 

OEMsr-228 

Cornell University 

Ithaca, N. Y. 

Apparatus for determination of particle size 

OEMsr-229 

Cornell University 

Ithaca, N. Y. 

Gelatinization of nitrocellulose 

OEMsr-239 

Pennsylvania State College 

State College, Pa. 

Supply contract 

OEMsr-243 

Pennsylvania State College 

State College, Pa. 

Synthesis of RDX 

OEMsr-244 

Pennsylvania State College 

State College, Pa. 

Compilation of data on explosives 

OEMsr-245 

University of Michigan 

Ann Arbor, Mich. 

Synthesis of RDX and picric acid 

OEMsr-273 

George Washington Univ. 

Rocket propellants 


Washington, D. C. 


OEMsr-305 

Columbia University 

New York, N. Y. 

Kinetics of nitration 

OEMsr-322 

Gulf Research & Development Company 
Pittsburgh, Pa. 

Igniters for gasoline-nitric acid mixtures 

OEMsr-334 

Harvard University 

Cambridge, Mass. 

Studies of detonations 

OEMsr-342 

Harvard University 

Cambridge, Mass. 

Mechanisms of formation of RDX 

OEMsr-351 

Gulf Research & Development Company 
Pittsburgh, Pa. 

Phlegmatization of RDX 

OEMsr-373 

E. I. du Pont de Nemours & Company 
Wilmington, Del. 

Ethyleneurea pilot plant 

OEMsr-393 

Tennessee Eastman Corp. 

Kingsport, Tenn. 

RDX pilot plant 

OEMsr-397 

Tennessee Eastman Corp. 

Kingsport, Tenn. 

Incorporation of RDX with TNT 

OEMsr-569* 

Woods Hole Oceanographic Institution 

Woods Hole, Mass. 

Underwater explosions 

OEMsr-59(i* 

Stanolind Oil & Gas Co. 

Tulsa, Okla. 

Gauges for measurement of shock waves 

OEMsr-616 

Ohio State University 

X-ray studies of RDX 


Columbus, Ohio 


OEMsr-639 

Monsanto Chemical Company 

Dayton, Ohio 

Pilot plant for moulded composite propellants 

OEMsr-640 

E. I. du Pont de Nemours & Company 

Pilot plant for production of ethyleneurea from 


Wilmington, Del. 

glycol 

OEMsr-643 

Rohm & Haas Company 

Philadelphia, Pa. 

Synthesis of polymers of nitro compounds 

OEMsr-64G 

University of Pennsylvania 

Philadelphia, Pa. 

Synthesis of RDX, picric acid, and DINA 

OEMsr-6G9 

University of Notre Dame 

Notre Dame, Ind. 

Addition of nitrogen oxides to ethylene 

OEMsr-701 

Indiana University 

Bloomington, Ind. 

Synthesis of DINA and other nitramines 

OEMsr-719 

Hercules Powder Company 

Wilmington, Del. 

Sensitivity of explosives 

OEMsr-741 

(Queens College 

Flushing, N. Y. 

Compilation of data on exj^losives 

*4Tansferrod to Division 2. 





176 


CONTRACT NUMBERS, CONTRACTORS, AND SUBJECT OF CONTRACT {Continued) 


Contract Number 


Contractor 


Subject 


OEMsr-751 

OEMsr-754 

OEMsr-7G3 

OEMsr-7()4 

OEMsr-705 

OEMsr-773 

OEMsr-700 

OEMsr-SOO 

OEMsr-828 

OEMsr-836 

OEMsr-859 

OEMsr-875 

OEMsr-881 

OEMsr-944* 

OEMsr-957 

OEIMsr-959 

OEiMsr-962 

OEMsr-97G 

OEMsr-1028 

OEMsr-104() 

OEMsr-1118 

OEMsr-112G 

OEMsr-1145 

OEMsr-1152 

OEMsr-121G 

OEMsr-122G 

OEMsr-1332 

OEMsr-1355 

OEMsr-14G2 

OEMsr-14G7 


Cornell University 
Ithaca, N. Y. 

University of Pittsbiirfi:h 
Pittsburgh, Pa. 

E. I. dll Pont de Nemours & Company 
Wilmington, Del. 

E. I. dll Pont de Nemours & Company 
Wilmington, Del. 

E. I. du Pont de Nemours & Company 
Wilmington, Del. 

Johns Hopkins University 
Baltimore, Md. 

\\anderbilt University 
Nashville, Tenn. 

Standard Oil Development Company 
New York, N. Y. 

E. I. du Pont de Nemours & Company 
Wilmington, Del. 

Eastman Kodak Company 
Rochester, N. Y. 

Hercules Powder Company 
Wilmington, Del. 

I diversity of Chicago 
Chicago, III. 

California Institute of Technology 
Pasadena, Calif. 

New York University 
New York, N. Y. 

Princeton University 
Princeton, N. J. 

Gulf Research and Development Company 
Pittsburgh, Pa. 

University of Pennsylvania 
Philadelphia, Pa. 

University of North Carolina 
Chapel Hill, N. C. 

Harvard I^ni versify 
Cambridge, Mass. 

University of Wisconsin 
Madison, Wis. 

E. I. du Pont de Nemours Com])any 
Wilmington, Del. 

Phillips Petroleum Company 
Bartlesville, Okla. 

Gulf Research & Development Company 
Pittsburgh, Pa. 

Ohio State University Research Foundation 
Columbus, Ohio 

American Aircraft Association 
Dayton, Ohio 

Metal & Thermit Corporation 
Rahway, N. J. 

E. I. du Pont de Nemours & Company 
Wilmington, Del. 

E. I. du Pont de Nemours & Company 
Wilmington, Del. 

Western Electric Company 
New York, N. Y. 

E. I. du Pont de Nemours <fe Company 
Wilmington, Del. 


I^nderwater explosions 

Measurements of heats of combustion of ex- 
plosives 

Preparation of special gun propellants 

Study of shaped charge weapons 

Haleite pilot plants 

Theory of shock waves 

Synthesis of nitramines 

Oils for desensitization of RDX 

Explosive streamer 

New sources of wood cellulose for nitration 

Explosive streamer 

Kinetics of nitration 

Chromatographic analysis of propellants 

Theory of shock waves 

Theory of detonations 

Shaped charge weapons 

Health hazards in RDX manufacture 

Theory of shock waves 

Polarographic analysis of explosives 

Polarographic analysis of exjilosives 

Design of an ethyleneurea plant 

Design of a cyclopentanone plant 

Ignition system for rocket propellants 

Decomposition products of nitrocellulose 

Jet propulsion motors 

Igniters and tracers 

DINA pilot plant 

Pilot plant for special gun propellants 

Development of an acoustical method for detec- 
tion of flaws in powder grains 
Development of inert simulants of explosives 


* Transferr(‘d to Applied Mathematics Panel. 


nr oXFI I) KX'I' I A i; 


177 


SERVICE PROJECT NUMBERS 


The projects listed below were transmitted to the Executive Secretary, 
National Defense Research Committee, NDRC, from the War or Navy 
Department through either the War Department Liaison Officer for 
NDRC or the Office of Research and Inventions (formerly the Co- 
ordinator of Research and Development), Navy Department. 


Service 

Project Title 

Number 


AC-75 


AN-1 

CE-30 

CE-32 

NA-103 

NA-197 

NO-BIO 

NO-B38 

NO-B39 

NO-B40 

NO-99 

NO-1 10 

NO-116 

NO-117 

NO-133 

NO-135 


NO-138 

NO-151 

NO-167 

NO-199 

NO-201 

NO-211 

NO-212 

NO-213 

NO-223 

NO-224 

NO-231 

NO-232 

NO-237 

NO-274 

NO-290 

NO-291 

NS-125 

NS-267 

NS-309 

OD-01 

OD-02 

OD-04 

OD-05 

OD-1 

OD-2 


The Development and Testing of Solid Propellants and Motors for Jet Propulsion Devices Requiring Large Pro- 
pellant Grains 
Shaped Charges 

Munroe Effect of Explosives. (Proj. cancelled) 

Project on the Development of a Hose Filled with Explosive for Mine Field Clearance 
Extended to include: “Indicator” Mine (a) Fabric Snake 
Self-Igniting Chemical for Jet Propulsion 

Development of Jet Assisted Take-Off Unit for Carrier Based Aircraft 
Development of New Explosives 
Mixing Methods for BWX and RDX 

Smokeless Powder, Wood Cellulose for Nitration, Conversion of Nitro-Cellulose into Smokeless Powder 
Phlegmatization of TNT for Loading AP Shells 
Jet Propulsion 
Controlled Fragmentation 

Extended to include: Fragmentation of Light Case Bombs or Rocket Ammunition 

Scatter Bomb for Submarine Attack by Heavier-than- Aircraft 

Process which will be Useful in Alleviating Phenol Shortage 

Coned Charges in: Antisubmarine Scatter-Bombs and Torpedo Warheads 

Flashless Powder Suitable for Use in 6" and 8” Navy Guns 

Extended to include: Albanite Powder 

Albanite Powder Granulation Samples 

Development of Certain Powder Samples of Albanite Cordite-N 
Determination of Proper Booster System for Large Explosive Charges. (Transferred to Division 2) 

Method of Loading Tracers 
Retardation of Projectile Fragments 
Study of Storage on TNT 
Effect of Heat on Confined Explosives 
Technique of Handling Composition A 
Development of Uniform Primacord 

Development of Propellant Powders for High Pressures and Densities of Loading 
Investigation of Explosives for Use in Underwater Munitions. (Transferred to Division 2) 

Theoretical Investigation of Explosion Phenomena. (Transferred to Division 2) 

Investigation of Physical and Chemical Properties of Aluminized Explosives 
Desensitization of Service Munitions 

Determination of Depth of Underwater Explosions from Surface Observations. (Transferred to Division 2) 

Stabilizers, Surveillance Methods, and Stability of Rocket Propellants 

Preparation and Testing of Military Explosives 

Optical Phenomena of Explosions 

Design of an Explosive Streamer 

NDRC Assistance in Underwater Explosion Measurements on Submarine Models. (Transferred to Division 2) 
3-inch Solid Slow-Burning Propellants. (Transferred to Division 3) 

Testing of Chemicals as Military High Explosives. Evaluation of Two (2) Types of Composition B/tetryl Explo- 
sives 

Basic Study of Detonations 

Fundamental Research in High Explosives Such as Phlegmatization, Etc. 

Special Propellants 

Study of Nitration of Furan and Derivatives 

Preparation of Nitroi)araffins and of Certain Derivatives Thereof 


178 


fTo K 


SERVICE PROJECT NUIMBERS {Continued) 


Service 

Project Title 

Number 


OD-3 Preparation of Amino Guanidine Sulfate and of Tetracene 

OD-4 Formaldehyde Condensations with Aldehydes and Ketones and Nitration of Products 
OD-5 A. Preparation of Nitrocyclohexane Derivatives 

B. Methods of Preparation of T.N.B., and 

C. Ethyleneimine Derivatives for Explosives and Toxic Substances 

OD-6 Preparation of Explosives from Ethylene Urea and Related Substances: Preparation of T.N.B. Amended 12-29-42 
to read: ‘‘Preparation of Explosives from Substances Relating to Ethyleneurea and Compounds Analogous 
Thereto” 

OD-7 Preparation of Explosives from Mono-, Di-, and Triethanolamines 
OD-S Preparation of Mixed Aliphatic-Aromatic Nitro Compounds and Nitrate Esters 

OD-9 Kinetics of Nitration of Toluene, Xylene, Benzene, and Ethylbenzene 

OD-10 A. Use of Acids Other Than SulKiric in Nitration Mixtures 
B. Preparation of T.N.B. : J/eto-Xylene from Crude Xylene 
OD-11 A. Preparation of Tetranitromethane 

B. Nitroform and Condensation Products 

C. Nitration of Ethylene and Acetylene 

OD-12 Nitration of Hexamethylene Tetramine and Analogous Compounds 

Extended to include: Chromatographic Determination of the HMX Content of RDX 
OD-13 Nitration of Naphthalene and Naphthol 

OD-14 Special Fuels for Jet Propulsion 

OD-15 Preparation of Special Compounds 

OD-21 Use of Oxyhydrogen as an Explosive 
OD-22 Research on Possible Source of Nitrocellulose 
OD-23 Nitration and its Relationship to Detonating or Tonal Wave 

OD-29 Preparation of Glucose Perchlorate and the Production of Glucose from Lignin Wastes 
OD-31 Improvement and Visibility of High Explosive Shell Bursts — Day and Night 
OD-44 Accelerants for the Gelatinization of Nitrocellulose 
OD-58 The Stability of PETN and its Mixture with TNT 

OD-68 Development of Raw Materials for the Manufacture of EDNA, Ethylenedinitramine 

OD-77 Suitability of N.I.P. as Substitute for Charcoal and Methods of Manufacturing 

OD-103 Development of a Composition C (RDX-C) Explosive having a Satisfactory Plasticity at Low Temperatures, 
Without Sacrifice of Sensitivity and Other Performance Characteristics 
OD-109 The Microscopic Method for the Qualitative Detection of Explosive Components 
OD-118 The Application of Polarographic Analysis to Military High Explosives 

OD-12G The Determination of the Structure of the Organic Intermediate Molecules Occurring in the Burning of Propellant 
Powders 

OD-131 Mine Case M3A1. (Transferred to Division 2) 

OD-152 Data on the Retardation of Fragments in the Air and Their Perforation of Steel Plate 
OD-158 Studies of Characteristics of New Double-Base Propellant Compositions 
OD-159 Development of Igniter-Tracer Units 

OD-188 High Impulse Light Weight Rocket Motors (Project declined April 13, 1945) 

OD-197 Development and Application of Cast Double Base Propellants 
OD-198 Development and Application of Composite Propellants 

OD-200 BBP Charge for Heavy-head M6A4 Type Rocket 
OD-201 Research on Elements of Rocktt Motors with High Impulse Ratio 
SC-41 Microwave Tube Destruction 

SOS-10 Investigation of Nitroso Guanidine and Other Compounds as Gas Generators 


ffioxTrij !■: .\Ti.\i; 


179 




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INDEX 


The subject indexes of all STR volumes are combined in a master index printed in a sei)arate volume. For 
access to the index volume consult the Army or Navy Agency listed on the reverse of the half-title page. 


AA shell bursts, increased visibility, G4 
Acidity detection and measurement, 
140-141 

Adiabatic ignition, 134 
Albanite powders, 106-110 

advantages over other powders, 108 
conclusions, 109-110 
cordite N, 107 
DDP mixture, 109 
DINA, 107-109 
formula, 108 
manufacture, 107-109 
OSRD pilot plant, 109 
performance tests, 109 
press explosions, 109 
selection of compounds, 107-108 
Aliphatic nitro compounds, 17-18, 27 
Aluminized explosives, 32-33, 56 
Baronal, 33 
dentex, 33 
gas evolution, 33 
HBX, 32 
pentonal, 33 
torpex-2; 32 
tritonals, 33 
Aminoalcohols, 26-27 
Aminoguanidine preparation, 28 
Analysis and identification of high ex- 
plosives, 48-49 
color tests, 48 
fusion analysis, 48-49 
optical crystallography, 48 
polarograph, 48 

Anhydroenneaheptitol pentanitrate, 
23-24 

Antisubmarine shaped-charge bomb, 
52-55 

bomb design, 52-53 
follow-through bomb, 53-55 
probable effectiveness, 53 
test target, 52-53 
Antitorpedo device. Holm, 59 
Applications of high explosives, 50-64 
AA shell bursts, incr eased visibility, 64 
Beano hand grenade, 58-59 
destruction of microwave tubes, 58 
explosive streamers, 59-60 
liquid explosives, 62-64 
shaped-charge bombs, 50-55 
shaped-charge boosters, 58 
shaped-charge follow-through rocket, 
57-58 

Aromatic nitro compounds, 18-19 

Baronal, aluminized explosive, 33 
Batch nitrolysis of hexamine, 3-4, 12 
Bazooka problem, 99-100 
Beano hand grenade, 58-59 
case, 59 
fillings, 59 
specifications, 58 


Benzene conversion to picric acid 
see Oxynitration of benzene to picric 
acid 

Bis-/3-nitroxyethylnitramine 
see DINA 

Booster-sensitivity test, 40 

Boys-Corner proposition on burning of 
propellants, 90-91 

British contributions to shaped charges 
see Shaped charges 

British plastic high explosive PE-1; 
28-30 

deterioration, 29 
preparation, 29 
properties, 28-29 
substitutes, 29-30 
uses, 28-29 

Burning theory for rocket powders, 89-95 

California Institute of Technology 
foreign propellants, 144-149 
smokeless powder properties, 143-144 
stability tests; see Stability of pro- 
pellants 

sjmthetic organic chemical work, 150 

Canadian process for RDX synthesis, 
6-7,9 

Cast double-base powder, 102-105 
composition, 103 
fabrication methods, 89 
outline of development, 102-103 
recommendations for future work, 
104-105 

restrictive containers, 104 
service evaluation, 104-105 

Cast perchlorate propellants, 101-102 
description of product, 101 
])rocess, 101 

recommended composition, 101 

Cavity charges, underwater penetra- 
tion, 74-76 
air space, 75 
charge length, 74-75 
explosive filling, 74-75 
liner shape, 75-76 
liner thickness, 75 
scaling laws, 75-76 

Cavity charges fired in air, 68-74 
aberrations, 72-73 
charge length, 68-69 
explosive filing, 68-69 
future developments, 73-74 
linear cavity charges, 73-74 
liner material, 70-72 
liner shape, 70 
liner thickness, 69 
scaling laws, 72 
spinning, 73 
stand-off, 69 
target material, 72 

Central! te 

ynVFIDKJSiTTTnTj 


determination in smokeless powder, 
124-125 

transformation products, 133-134 
Chapman-Jouguet hypothesis, detona- 
tion velocity, 84 

Chemical and physical powder analysis, 
122-127 

Chemical igniter system for jet-propul- 
sion devices, 150 

Chromatographic - spectrophotometric 
methods for analyzing propel- 
lants, 127-134 

analyses of foreign i)ropellants, 131- 
132 

application to smokeless powder 
studies, 128-134 

centralite transformation products, 
133-134 

description of chromatographic 
method, 127-128 

detection of unfamiliar compounds, 
131-132 

development history, 127 
diphenylamine transformation i)rod- 
ucts, 132-133 
ether removal, 129 
ligroin, 129 

pre-washing treatment, 129-130 
routine analysis, 131-135 
silicic acid, 128 
soxhlet apparatus, 128 
streak reagents, 129 
transformation of stabilizers, 132-134 
Chromatography for determination of 
HMX in RDX (B), 11 
Color tests for identification of explos- 
ives, 48 

Combination process for RDX (B) 
preparation 

see RDX (B) preparation by combi- 
nation process 
Combustion heats, 47 
Composite propellants 
perchlorate, 93-94 
suggestions for future work, 94-95 
theory of burning, 93-94 
Composite propellants, solvent-ex- 
truded 

see Solvent-extruded composite pro- 
pellants 

Continuous nitrolysis of hexamine, 
3-6, 12 

Covolume constant determination, 87 
Crawford contributions to rocket pow- 
der burning, 89-90 

Cyclotetramethyl enetetrani tramine , 8 

Detonation process, theory, 83-88 
Chapman-Jouguet hypothesis, 84 
composition of explosion reaction 
products, 87 

181 


182 


INDEX 


CO volume constants, 87 
detonation pressures, 88 
detonation velocity, 86-87 
equation of state, 85-86 
initial shock wave velocity, 86 
Rankine-Hugoniot formulation, 84 
rarefaction waves, 86 
Riemann formulation, 83-84 
Detonation velocity for explosives, 44- 
47, 86-87 

ammonium jiicrate, 46-47 
experiment description, 45-46 
experiment results, 46 
nitrate explosives, 46-47 
rate of chemical reaction, 44-45 
reaction zone length, 47 
Devarda procedure for nitrogen estima- 
tion, 123 

Diazonium salt, 22-23 
DINA (bis-/3-nitroxyeth3'lnitramine) 
preparation, 14-16 
by-products, 15-16 
catalyst, 15 

quality of raw materials, 15 
DINA propellants, 107-109, 122 
Diphenylamine, consecutive transform- 
ation, 135-137 

Diphenylamine, determination in 
smokeless powder, 125 
chromatographic procedures, 125 
nitric acid-digestion procedure, 125 
soda-distillation procedure, 125 
Dii)henylamine transformation prod- 
ucts, 132-133 

Double-base •powders, burning theory, 
90-94 

•Boys-Corner proposition, 90-91 
burning rate-pressure curve, 92 
burning stages, 90 
composite propellants, 93-95 
effect of coolants, 92-93 
equation of parameter, 92 
fizz burning process, 90-91 
flame, effect on burning process, 91 
future work, 93 

reaction times and distances, 93 
Double-base powders, cast 
see Cast double-base powder 
Double-base powders, solventless, 113- 
122 

small batch preparation, 119 
smokeless powder studies, 122 
stability, 120-121 
DuPont nitrometer, 123 

Einheits rocket ])ropellant composition, 
148-149 

EJA i)owder, 100 

Electromagnetic impact fuze, 81-82 
Erosion factors for motor nozzles, 105- 
106 

Ethylenedinitramine 
see Haleite 

Ethyleneurea synthesis, 13 
Experimental powders, preparation, 
148-149 

Experimental studies, explosive phe- 
nomena 


sec Explosive phenomena, experimen- 
tal studies 

Exj)losion temperature tests, 36 
Ex])losive compositions, 30-32 
British composition A, 30 
British composition B, 30-32 
ednatols, 32 

Explosive phenomena, experimental 
studies, 65-82 
flash photography, 65 
shaped charges, 67-82 
shell fragmentation, 65-67 
Explosive plasticizers, 119-120, 122 
Explosive streamers, 59-60 
density requirements, 61-62 
design problems, 60 ^ 

filler, 60 

flexed inner hose, 60-61 
Mark 29 mine, 59 
outer hose, 60-61 
slurry-type explosives, 61-62 
TXT canvas-sock load, 61 
Explosives Research Laboratory 
(ERL), 38-40 
booster-sensitivity test, 40 
bullet-impact tests, 40 
drop-weight impact tests, 38-40 
l^erformance of explosives, 44 
sensitiveness data, 39 
shaped-charge bombs, 50-55 
shell-impact tests, 40 
Extrusion press, 117-118 

Fivonite, 24-25 
advantages, 24 
preparation, 24-25 
Flash photography, 65 
Follow-through bomb, antisubmarine 
shaped-charge, 53-55 
design, 54-55 

forward charge, size and shape, 54 
propulsion, 54-55 
timing of explosive elements, 55 
Foreign propellants, examination, 121, 
131-132, 144-149 

analysis procedure, 131-132, 145-146 
linear burning rates, 121, 146-148 
preparation of experimental powders, 
148-149 

Fractionation of nitrocellulose, 111-112 
Fusion analysis method for high ex- 
plosives, 48-49 

Fuzing of shaped-charge weapons, 80- 
82 

electromagnetic impact fuze, 81-82 
fuzed delay reduction, 80 
preserving stand-off, 80 
spit-back fuze, 80-81 

Gas evolution from aluminized exj^lo- 
sives 

gassing, definition, 33 
minol and DBX gassing, 33 
spewing, definition, 33 
torpex gassing, 33 
tritonal gassing, 33 
Gas evolution of explosives, 139-140 
German gun propellants, 146 


German rocket propellants, 145, 147- 
149 

Haleite (ethylenedinitramine) prepara- 
tion, 12-14 

cost limitations, 12, 13 
ethylenediamine synthesis, 13 
ethylenediamine to ethyleneurea con- 
version, 13 

ethylenediamine-carbon dioxide re- 
action 13-14 

ethyleneurea synthesis, 13 
])referred total synthesis, 14 
Haleite stability, 37 
HBX aluminum explosive, 32 
Heats of combustion, 47 
Hercules Experiment Station, sensitive- 
ness studies, 40-43 

detonation by initiating explosives, 
42 

friction, 41-42 
glancing impact, 42 
impact, 41 
rifle bullets, 42-43 
sensitiveness table, 43 
Hexamine 

batch nitrolysis, 3, 4, 12 
continuous nitrolysis, 3-6, 12 
High explosives, preparation 

see Preparation of high explosives 
HMX (cyclotetramethylenetetranitra- 
mine), 8 

see also RDX (B) preparation by 
combination process 
Holm antitorpedo device, 59 
Hydrodynamics equations, Rieman for- 
mulation, 83-84 
Hygroscopicity test, 35 

Identification and analysis of high ex- 
plosives 
color tests, 48 
fusion analysis, 48-49 
optical crystallography, 48 
polarograph, 48 
Igniters, 151-152 
Impact tests 

bullet-impact, 40 
drop-w'eight, 38-40 
shell-impact, 40 

Japanese rocket propellants, 145-148 
Japanese shell propellant, 146 
JB-2 bomb launching unit, 98 
Jet formation, 76-77 
Jet velocities (shaped-charges), 79 

Ligroin in chromatography, 129 
Linear burning rates of foreign propel- 
lants, 121, 146-148 
measuring apparatus, 146-147 
results of measurements, 147-148 
testing procedure, 146-147 
Linear burning rates of propellant pow^ 
ders, 121 

Linear cavity charges, 73-74 
Liquid explosives, 62-64 


{u mlDEXTIA'L 


INDEX 


183 


deseiL^itized nitroglycerin composi- 
tions, 02 

dispersing devices, 63 
requirements, 62 
sensitivities, 63 

Mark 29 mine, 59 
Microwave tube destruction, 58 
MJA powder, 100 

Moisture determination in solventless 
double-base powder 
carbon tetrachloride distillation, 126 
cone-and-disk procedure, 126 
desiccation method, 126 
Karl Fischer j)rocedures, 126 
Molded composite propellants, 95-99 
advantage over conventional pro- 
])ellants, 95-96 
Dritish work, 95 
composition changes, 96-98 
launching unit for JB-2 bomb, 98 
pilot plant studies, 97-99 
production techniques, 96-97 
Molecular weight and distribution in 
nitrocellulose, 112-113 
light scattering measurements, 113 
molecular heterogeneity, 112-113 
osmotic pressure measurements, 112 
viscosity measurements, 112 
Monsanto pilot plant, 98-99 
Motor nozzles, 105-106 
design requirements, 105-106 
erosion factors, 105-106 
material tests, 106 

Naval torpedo warheads, 55-56 
New propellants, 122 
Nitramide preparation, 16 
Nitramine preparation, 16-17 
Nitramine-nitrate ester preparation, 17 
Nitrate esters, 23-25, 27 
anhydroenneaheptitol pentanitrate, 
23-24 

fivonite, 24-25 
pentaerythritol (PE), 24 
Nitric esters, estimation in powder, 124 
Nitrocellulose determination proced- 
ures, 122-123 

Nitrocellulose studies, 111-113 
artificially aged powders, 113 
chemical characterization, 111-112 
fractionation, 111-112 
- molecular weight, 112-113 
preparation of samples. 111 
X-ray studies, 113 
Nitrofurans, 28 

Nitrogen dioxide stability test, 142 
Nitrogen estimation in nitrocellulose, 
123 ’ 

Nitroglycerin separation from double- 
base powders, 150 

Nitrolysis of hexamine, direct process, 
3-6, 12 

batch nitrolysis, 3, 4, 12 
British process, 6 
continuous nitrolysis, 3-6, 12 
cyclonite isolation effects, 6 
fume-off method, 4 


hexamine addition time, 5-6 
holding time, 5-6 
imj^ortant variables, 5-6 
nitric acid purity, 5 
nitric acid strength, 5 
reaction temperature, 5 
stirring, 5-6 

Nitrometer, DuPont, 123 
Nonexplosive plasticizers, 119 
Nonvolatile inorganic constituent de- 
termination in smokeless powd- 
er, 126-127 
Nozzles, 105-106 


Optical crystallography method in anal- 
ysis of high explosives, 48 
Oxvnitration of benzene to picric acid, 
19-23 

continuous extraction jirocess, 21-22 
continuous solution process, 21 
diazonium salt, 22-23 
effective benzene concentration, 19- 
20 

mercuric nitrate catalyst concentra- 
tion, 20 

nitration of phenols, 23 
nitric acid concentration, 19-20 
nitrosobenzene, 22-23 
preparatory procedures, 21-22 
reaction mechanisms, 22-23 
reaction temiierature, 20 


PE-1, British plastic explosive, 28-30 
deterioration, 29 
preparation, 29 
properties, 28-29 
substitutes, 29-30 
uses, 28-29 

Penetration velocities, shaped-charge 
jets, 79 

Pennsylvania State College, prepara- 
tion of high explosives, 3-4 
Pentaerythritol (PE), 24 
Pentolite stability, 37 
Perchlorate as filler for composite pro- 
pellants, 93-94 

Perchlorate propellants, cast, 101-102 
Performance of explosives, 44, 45 
ballistic mortar, 44 
plate-denting test, 44 
PETN propellants, 122 
pH measurements, 140-141 
Physical properties of smokeless i)ow- 
ders 

see Smokeless powders, jihysical 
I)roperties 
Picric acid 

see Oxynitration of benzene to picric 
acid 

Pilot plant development for RDX (B) 
preparation, 9-10 
Plastic high explosives, 28-30 
British PE-1; 28-30 
PEP-3; 30 
PIPE, 30 
RIPE, 30 

table of properties, 31 


Plasticizers 

explosive, 119-120, 122 
nonexplosive, 119 

Polarograph, 48 

Polymers, ex])losive and combustible, 
25-26 

nitroindene polymer (NIP), 25 
preparation as binders, 25-26 
uses, 25 

Powder, small batch jireparation, 113- 
118 

Powder analysis 

chemical and physical methods, 122- 
127 

chromatographic-spectrophotometric 
methods, 127-134 

nitric esters and nitro compounds, 
124 

nitrocellulose determination pro- 
cedures, 122-123 

nitrogen estimation in nitrocellulose, 
123 

quantitative estimation of stabilizers 
and nonexplosive plasticizers, 
124-126 

quantitative estimation of volatile 
and inorganic constituents, 126- 
127 

Preparation of experimental powders, 
148-149 

Preparation of high exi)losives, 3-33, 
113-118 

aliphatic nitro compounds, 17-18 
aliphatic-aromatic-nitro compounds 
and nitrate esters, 27 
aluminized explosives, 32-33 
aminoalcohols, 26-27 
aminoguanidine, 28 
aromatic nitro compounds, 18-19 
DINA, 14-16 

explosive and combustible polymers, 
25-26 

explosive compositions, 30-32 
haleite (ethylenedinitramine), 12-14 
nitramides, 16 
nitramine-nitrate esters, 17 
nitramines, 16-17 
nitrate esters, 23-25 
nitrofurans, 28 

oxynitration of benzene to picric 
acid, 19-23 

])lastic high explosives, 28-30 
RDX (B) preparation by combina- 
tion ])rocess, 6-12 

RDX preparation by direct nitrolysis 
of hexamine, 3-6 
trinitro-m-xylene, 28 

Primer compositions, analysis, 152 

Production techniques for molded com- 
posite propellants, 96-97 

Propellants, 89-150 

albanite powders, 106-110 
analysis of powders, 122-134 
burning of rocket powders, theory, 
89-95 

cast double-base powder, 102-105 
cast perchlorate propellants, 101-102 
chemical igniter system, 150 


Confidential, ) 


184 


INDEX 


forei^in propellants, 131-132, 144-140 
linear burning rates, 121 
molded composite propellants, 95-90 
motor nozzle design and materials, 
105-106 

nitrocellulose studies, 111-113 
])artial burning, 149-150 • 
preparation of small batches, 113-118 
RDX powders, 110-111 
separation of nitroglycerin from 
double-base powders, 150 
smokeless powders, 143-144 
solvent-extruded composite propel- 
lants, 99-101 

solventless double-base powders, 113- 
122 

stability, 134-142 

synthetic organic chemical work, 150 
thermochemical properties, 149 
Properties of high explosives, 34-49 
classified reports listing, 34 
detonation velocity, 44-47 
heats of combustion, 47 
identification and analysis, 48-49 
performance, 44, 45 
sensitiveness, 38-43 
stability, 35-38 
Purity test, 35 

Rankine-Hugoniot formulation, deto- 
nation, 84 

RDX composition A, 30 
RDX powders, 110-111 
early trials, 110-111 
manufacture, 110-111 
selection of compositions, 110 
RDX preparation, 3-12 
combination process, 6-12 
direct nitrolysis of hexamine, 3-6 
Pennsylvania State College investi- 
gations, 3-4 

RDX (B) preparation by combination 
process, 6-12 
acid recovery, 10 
analytical and test methods, 1 1 
Canadian process, 6-7, 9 
chromatography, 11 
continuous process description, 10 
health hazard, 11 
HMX addition, 8 
pilot plant development, 9-10 
})rocess comparisons, 12 
raw materials requirement, 1 1 
reaction mechanism, 8-9 
refining, 10-11 
special problems, 11 
RDX ])ropellants, 122 
RDX-TNT comj)osition B, 30-32 
Riemann formulation of hydrodynam- 
ics ecpiations, 83-84 
Rocket, shaped-charge, 57-58 
Rocket ])owders, theory of burning, 89- 
95 

composite propellants, 93-95 
Dr. B. L. Crawford, Jr., 89-90 
double-base powders, 90-94 
Rocket propellants, German, 145, 147- 
149 


Rocket i)ropellants, Japanese, 145-148 
Rocket safe test for shipboard use, 142 
Rolling mill 
one-inch 116 
three-inch, 116-117 

Sensitiveness of high explosives, 38-43 
booster sensitivity, 40 
bullet impact, 40, 42-43 
detonation by initiating explosives, 
42 

drop-weight impact, 38-39 
friction, 41 
impact, 41 
shell impact, 40 
Shaj^ed charges, 67-82 

cavity charges fired in air, 68-72 
development history, 67-68 
fuzing, 80-82 
jet formation, 76-77 
jet velocities, 79 
penetration velocities, 79 
shaped detonation waves, 80 
target penetration theory, 77-79 
underwater penetration by cavity 
charges, 74-76 
Shaped detonation waves 
baratol-core, 80 
j^entolite shell, 80 
TNT core, 80 

Shaped-charge bombs, 50-55 
antisubmarine bomb, 52-53 
cone construction, 51 
fuzing problem, 51 
tests against model ships, 50-52 
Shaped-charge follow-through rocket, 
57-58 

Shaped-charge jets, penetration veloci- 
ties, 79 

Sha])ed-charge warheads for naval tor- 
pedoes, 55-56 
aluminized explosives, 56 
cone, 56 

Mark 13 warhead, 56 
test targets, 55-56 

Shaped-charge weapons, fuzing, 80-82 
electromagnetic impact fuze, 81-82 
fuze delay reduction, 80 
preserving stand-off, 80 
spit-back fuze, 80-81 
Shell bursts (AA), increased visibility, 
64 

Shell fragmentation studies, 65-67 
casing thickness, 66 
data requirements, 65-66 
detonating chamber, 66 
fragment retardation, 66 
fragment velocity measurements, 66 
relative effectiveness of explosives, 
66-67 

wall thickness, 66, 67 
Shock wave velocity, 86 
Slurries for small batches of solventless 
double-base powders, 113-117 
mixing, 114-116 
one-inch rolling mill, 116 
three-inch rolling mill, 116-117 
Slurry-type explosives, 61-62 


Small batch preparalion of janvder, 
113-118 

Smokeless ])owder st udies 

api)lication of chromatograi)hic-si)ec- 
tro])hotonietric methods, 128- 
134 

centralite determination, 124-125 
determination of diphenylamine, 125 
explosive i)lasticizers, 119-120, 122 
foreign propellants, 121 
linear burning rates, 121 
new })ropellants, 122 
nitrocellulose and strength of JPII- 
type ballistites, 119-120 
nonexplosive plasticizers, 119 
stability of double-base powders, 
120-121 

Smokeless powders, estimation of 
available nitrate, 142 
Smokeless powders, physical i)roperties 
effect of nitrocellulose character, 
143-144 

investigation results, 144 
measurements, 144 
Sock loading, TNT, 61 
Solvent-extruded composite propel- 
lants, 99-101 

basis for research program, 99 
bazooka problem, 99-100 
composition and ballistic j^roperties, 
101 

EJA powder, 100 
experimental plant, 100-101 
MJA powder, 100 
preparation techniques, 100 
Solventless double-base powders, 113- 
122 

small batch jneparation, 113-118 
smokeless powder studies, 119-122 
Spit-back fuse (sha])ed-charge), 80-81 
Stability of double-base powder, 120- 
121 

Stability of high explosives, 35-38 
haleite, 37 
pentolite, 37 

special stability problems, 36-38 
tests, 35-36 

Stability of propellants, 134-142 
adiabatic ignition, 134 
consecutive transformation of di- 
phenylamine, 135-137 
estimation of available nitrate in 
smokeless powder, 142 
heat test, 141 

measurements of pH, 140-141 
nitrogen dioxide stability test, 142 
jnogram outline, 134-135 
rocket safe test for shipboard use, 142 
stabilizer depletion in heated pow- 
ders, 137-139 
surveillance test, 141 
taliani-type test, 140 
vacuum stability test, 139-140 
Stability tests for explosives, 35-36 
explosion temperature, 36 
hygroscopicity, 35 
international test, 35 
purity, 35 


INDEX 


185 


surveillance, 36 
thermal stability, 35 
vacuum stability, 35-36 
Stabilizer depletion in heated powders, 
137-139 

Stabilizer transformations, 132-134 
Streak reagents, 129 
Streamers, explosive 
see Explosive streamers 
Surveillance tests for stability, 36, 
141 

Synthetic organic chemical work, 150 

Taliani-type test, 140 
Target penetration theory, shaped 
charge jets, 77-79 


Theory of burning of rocket powders, 
89-95 

composite propellants, 93-95 
Dr. B. L. Crawford, 89-90 
double-base powders, 90-94 
Theory of detonation process 
see Detonation process, theory 
Thermal stability test, 35 
TNT canvas-sock load, 61 
Torpex gassing, 33 
Torpex-2, aluminized explosive, 32 
Tracers, 151-152 

Transformations of stabilizers, 132-134 
Trinitro-m-xylene preparation, 28 

Underwater penetration by cavity 
charges, 74-76 


air space, 75 
charge length, 74-75 
explosive filling, 74-75 
liner shape, 75-76 
liner thickness, 75 
scaling, 75-76 

Vacuum stability test, 35-36, 139- 
140 

Viscosity measurements for nitrocellu- 
lose molecular weight studies, 
112-113 

Warheads for naval torpedoes (shaped- 
charge), 55-56 

X-ray diffraction powder photo- 
graphs, 123 


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